UNITEDSTATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN ISSUER
PURSUANT TO RULE 13a-16 OR 15d-16 OF
THE SECURITIES EXCHANGE ACT OF 1934

For the month of August 2025

Commission file number: 001-38423

SUNLANDSTECHNOLOGY GROUP

(Exact Name of Registrant as Specified in Its Charter)

Building 6, Chaolai Science Park, No. 36

Chuangyuan Road, ChaoyangDistrict

Beijing, 100012, thePeople’s Republic of China

+86-10-52413738

(Address of Principal Executive Offices)

Indicate by check mark whether the registrant files or will file annualreports under cover Form 20-F or Form 40-F.    Form 20-F  ☒       Form40-F  ☐

EXHIBIT INDEX

Signature

Pursuant to the requirements of the SecuritiesExchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto duly authorized.

Exhibit 99.1

Sunlands TechnologyGroup Announces Unaudited 

Second Quarter2025 Financial Results

BEIJING, August 14,2025 -- Sunlands Technology Group (NYSE: STG) (“Sunlands” orthe “Company”), a leader in China’s adult online education market and China’sadult personal interest learning market, today announced its unaudited financial resultsfor the second quarter ended June 30, 2025.

Second Quarter 2025Financial and Operational Snapshots

¹Net income margin is defined as net income as a percentage of net revenues.

²New student enrollments for a given period refer to the total number of orders placed by students that newly enroll in at least one courseduring that period, including those students that enroll and then terminate their enrollment with us, excluding orders of our low-pricecourses, such as “mini courses” and “RMB1 courses”, which we offer in the form of recorded videos or short livestreaming, to strengthen our competitiveness and improve customer experience.

“In the second quarter of 2025, our netrevenues reached RMB539.0 million, up 9.5% year-over-year, supported by resilient learner demand and the continued expansion of our courseofferings. Net income surged to RMB126.6 million, with net income margin expanding to 23.5%—representing a 54.0% increase from thesame period last year. This marked a significant step-change in our earnings capacity, reflecting the compounding effects of structuralcost optimization, improved gross margin, and greater operating leverage. Our deliberate rebalancing of legacy and emerging businesses,combined with disciplined investment in high-impact areas, is creating meaningful value for both learners and shareholders.

Looking ahead, Sunlands remains committed to responsibleand sustainable growth. We will continue to deepen AI integration across core operations, while expanding personalized, outcome-drivenlearning solutions tailored to the shifting needs of China’s adult learners—ranging from career upskilling to interest-basedenrichment and lifelong development,” said Mr. Tongbo Liu, Chief Executive Officer of Sunlands.

Mr. Hangyu Li, Finance Director of Sunlands, commented,“Our second quarter results are strong and in line with expectations. This quarter, net revenues rose 10.5% quarter-over-quarter,a direct outcome of our strategic shift toward interest-based courses which now account for 77.6% of total revenues. Withpositive operating cash flow for eight quarters, we maintained substantial cash reserves as of quarter-end. This strong financial positionempowers us to innovate and capture growth opportunities in an increasingly competitive market environment. Moving forward, weremain focused on sustaining high-quality earnings, driving operational efficiency, and making strategic investments in innovation tounlock new areas of growth.”

Financial Results for the second Quarter of2025

Net Revenues

In the second quarter of 2025, net revenues increasedby 9.5% to RMB539.0 million (US$75.2 million) from RMB492.2 million in the second quarter of 2024. The increase was primarily driven bythe growth in gross billings from interest courses.

Cost of Revenues

Cost of revenues decreased by 9.1% to RMB69.6million (US$9.7 million) in the second quarter of 2025 from RMB76.6 million in the second quarter of 2024. The decrease was mainly dueto the declined compensation expenses related to headcount reduction of the Company’s teachers and mentors for degree- or diploma-orientedpost-secondary courses.

Gross Profit

Gross profit increased by 12.9% to RMB469.4 million(US$65.5 million) in the second quarter of 2025 from RMB415.6 million in the second quarter of 2024.

Operating Expenses

In the second quarter of 2025, operating expenseswere RMB342.6 million (US$47.8 million), representing a 1.1% increase from RMB338.9 million in the second quarter of 2024.

Sales and marketing expenses increased by 1.7%to RMB302.5 million (US$42.2 million) in the second quarter of 2025 from RMB297.4 million in the second quarter of 2024.

General and administrative expenses decreasedby 2.0% to RMB33.2 million (US$4.6 million) in the second quarter of 2025 from RMB33.8 million in the second quarter of 2024.

Product development expenses decreased by 9.3%to RMB6.9 million (US$1.0 million) in the second quarter of 2025 from RMB7.7 million in the second quarter of 2024. The decrease was mainlydue to declined compensation expenses related to headcount reduction of the Company’s product development personnel.

Net Income

Net income for the second quarter of 2025 wasRMB126.6 million (US$17.7 million), as compared to RMB82.3 million in the second quarter of 2024.

Basic and Diluted Net Income Per Share

Basic and diluted net income per share was RMB18.75(US$2.62) in the second quarter of 2025.

Cash, Cash Equivalents, Restricted Cash andShort-term Investments

As of June 30, 2025, the Company had RMB586.7million (US$81.9 million) of cash, cash equivalents and restricted cash and RMB166.6 million (US$23.3 million) of short-term investments,as compared to RMB507.2 million of cash and cash equivalents and RMB276.0 million of short-term investments as of December 31, 2024.

Deferred Revenue

As of June 30, 2025, the Company had a deferredrevenue balance of RMB814.3 million (US$113.7 million), as compared to RMB916.5 million as of December 31, 2024.

Share Repurchase

On December 6, 2021, the Company’s boardof directors authorized a share repurchase program, under which the Company may repurchase up to US$15.0 million of Class A ordinary sharesin the form of ADSs over the next 24 months. On December 1, 2023, the Company’s board of directors authorized to extend its sharerepurchase program over the next twenty-four months. As of August 11, 2025, the Company had repurchased an aggregate of 760,155 ADSs forapproximately US$4.4 million under the share repurchase program.

Financial Results for the First Six Monthsof 2025

Net Revenues

In the first six months of 2025, net revenuesincreased by 1.1% to RMB1,026.6 million (US$143.3 million) from RMB1,015.5 million in the first six months of 2024.

Cost of Revenues

Cost of revenues decreased by 7.7% to RMB142.0million (US$19.8 million) in the first six months of 2025 from RMB153.8 million in the first six months of 2024. The decrease was mainlydue to the declined compensation expenses related to headcount reduction of the Company’s teachers and mentors.

Gross Profit

Gross profit increased by 2.7% to RMB884.7 million(US$123.5 million) from RMB861.7 million in the first six months of 2024.

Operating Expenses

In the first six months of 2025, operating expenseswere RMB683.8 million (US$95.5 million), representing a 0.5% increase from RMB680.1 million in the first six months of 2024.

Sales and marketing expenses increased by 0.7%to RMB603.0 million (US$84.2 million) in the first six months of 2025 from RMB599.0 million in the first six months of 2024.

General and administrative expenses increasedby 1.8% to RMB67.6 million (US$9.4 million) in the first six months of 2025 from RMB66.4 million in the first six months of 2024.

Product development expenses decreased by 10.1%to RMB13.2 million (US$1.8 million) in the first six months of 2025 from RMB14.7 million in the first six months of 2024. The decreasewas mainly due to declined compensation expenses related to headcount reduction of the Company’s product development personnel.

Net Income

Net income for the first six months of 2025 wasRMB201.8 million (US$28.2 million), compared with RMB195.0 million in the first six months of 2024.

Basic and Diluted Net Income Per Share

Basic and diluted net income per share was RMB29.87(US$4.17) in the first six months of 2025, compared with RMB28.44 in the first six months of 2024.

Outlook

For the third quarterof 2025, Sunlands currently expects net revenues to be between RMB500 million to RMB520 million, which would represent an increase of1.8% to 5.8% year-over-year. The above outlook is based on the current market conditions and reflects the Company’s current andpreliminary estimates of market and operating conditions and customer demand, which are all subject to substantial uncertainty.

Exchange Rate

The Company’s business is primarily conductedin China and all revenues are denominated in Renminbi (“RMB”). This announcement contains currency conversions of RMB amountsinto U.S. dollars (“US$”) solely for the convenience of the reader. Unless otherwise noted, all translations from RMB to US$are made at a rate of RMB7.1636 to US$1.00, the effective noon buying rate for June 30, 2025 as set forth in the H.10 statistical releaseof the Federal Reserve Board. No representation is made that the RMB amounts could have been, or could be, converted, realized or settledinto US$ at that rate on June 30, 2025, or at any other rate.

Conference Call and Webcast

Sunlands’management team will host a conference call at 6:00 AM U.S. Eastern Time, (6:00 PM Beijing/Hong Kong time) on August 14, 2025, followingthe quarterly results announcement.

Forparticipants who wish to join the call, please access the link provided below to complete online registration 15 minutes prior to thescheduled call start time. Upon registration, participants will receive details for the conference call, including dial-in numbers, apersonal PIN and an e-mail with detailed instructions to join the conference call.

RegistrationLink:

https://register-conf.media-server.com/register/BI138527c50562419dbce86de3604c0e10

Additionally,a live webcast and archive of the conference call will be available on the Investor Relations section of Sunlands’ website at https://ir.sunlands.com/.

About Sunlands

Sunlands Technology Group(NYSE: STG) (“Sunlands” or the “Company”), formerly known as Sunlands Online Education Group, is a leader in China’sadult online education market and China’s adult personal interest learning market. With a one to many live streaming platform, Sunlandsoffers various degree- or diploma-oriented post-secondary courses as well as professional certification preparation, professional skillsand interest courses. Students can access the Company’s services either through PCor mobile applications. The Company’s online platform cultivates a personalized, interactivelearning environment by featuring a virtual learning community and a vast library of educational content offerings that adapt to the learninghabits of its students. Sunlands offers a unique approach to education research and development that organizes subject content into LearningOutcome Trees, the Company’s proprietary knowledge management system. Sunlands hasa deep understanding of the educational needs of its prospective students and offers solutions that help them achieve their goals.

About Non-GAAPFinancial Measures

We use gross billings,EBITDA, non-GAAP operating cost and expenses, non-GAAPincome from operations and non-GAAP net income per share, each a non-GAAP financialmeasure, in evaluating our operating results and for financial and operational decision-making purposes.

We define gross billingsfor a specific period as the total amount of cash received for the sale of course packages, net of the total amount of refunds paid insuch period. Our management uses gross billings as a performance measurement because we generally bill our students for the entire coursetuition at the time of sale of our course packages and recognize revenue proportionally over a period. EBITDA is defined as net incomeexcluding depreciation and amortization, interest expense, interest income, and income tax expenses. We believe that gross billings andEBITDA provide valuable insight into the sales of our course packages and the performance of our business.

Thesenon-GAAP financial measures should not be considered in isolation from, or as a substitute for, their most directly comparable financialmeasures prepared in accordance with GAAP. A reconciliation of the historical non-GAAP financial measures to their respective most directlycomparable GAAP measure has been provided in the tables included below. Investors are encouraged to review the reconciliation of the historicalnon-GAAP financial measures to their respective most directly comparable GAAP financial measures. As gross billings, EBITDA, operatingcost and expenses excluding share-based compensation expenses, general and administrative expenses excluding share-based compensationexpenses, sales and marketing expenses excluding share-based compensation expenses, productdevelopment expenses excluding share-based compensation expenses, income from operationsexcluding share-based compensation expenses, and basic and diluted net income per share excludingshare-based compensation expenses have materiallimitations as an analytical metric and may not be calculated in the same manner by all companies, it may not be comparable to other similarlytitled measures used by other companies. In light of the foregoing limitations, you should not consider gross billings and EBITDA as asubstitute for, or superior to, their respective most directly comparable financial measures prepared in accordance with GAAP. We encourageinvestors and others to review our financial information in its entirety and not rely on a single financial measure.

Safe Harbor Statement

This press release contains forward-looking statementsmade under the “safe harbor” provisions of Section 21E of the Securities Exchange Act of 1934, as amended, and the U.S. PrivateSecurities Litigation Reform Act of 1995. These forward-looking statements can be identified by terminology such as “will,”“expects,” “anticipates,” “future,” “intends,” “plans,” “believes,”“estimates,” “confident” and similar statements. Sunlands may also make written or oral forward-looking statementsin its reports filed with or furnished to the U.S. Securities and Exchange Commission, in its annual report to shareholders, in pressreleases and other written materials and in oral statements made by its officers, directors or employees to third parties. Any statementsthat are not historical facts, including statements about Sunlands' beliefs and expectations, are forward-looking statements that involvefactors, risks and uncertainties that could cause actual results to differ materially from those in the forward-looking statements. Suchfactors and risks include, but not limited to the following: Sunlands’ goals and strategies;its expectations regarding demand for and market acceptance of its brand and services; its ability to retain and increase student enrollments;its ability to offer new courses and educational content; its ability to improve teaching quality and students’ learning results;its ability to improve sales and marketing efficiency and effectiveness; its ability to engage, train and retain new faculty members;its future business development, results of operations and financial condition; its ability to maintain and improve technology infrastructurenecessary to operate its business; competition in the online education industry in China; relevant government policies and regulationsrelating to Sunlands’ corporate structure, business and industry; and general economic and business condition in China. Furtherinformation regarding these and other risks, uncertainties or factors is included in Sunlands’filings with the U.S. Securities and Exchange Commission. All information provided in this press release is current as of the date ofthe press release, and Sunlands does not undertake any obligation to update such information, except as required under applicable law.

For investor and mediaenquiries, please contact:

Sunlands Technology Group

Investor Relations

Email: sl-ir@sunlands.com

SOURCE: Sunlands TechnologyGroup

SUNLANDS TECHNOLOGYGROUP

UNAUDITED CONDENSEDCONSOLIDATED BALANCE SHEETS

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UNAUDITED CONDENSEDCONSOLIDATED STATEMENTS OF OPERATIONS 

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UNAUDITED CONDENSEDCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME 

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RECONCILIATION OF GAAPAND NON-GAAP RESULTS

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UNAUDITED CONDENSEDCONSOLIDATED STATEMENTS OF OPERATIONS

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SUNLANDS TECHNOLOGYGROUP 

UNAUDITED CONDENSEDCONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME 

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SUNLANDS TECHNOLOGYGROUP

RECONCILIATION OF GAAPAND NON-GAAP RESULTS

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