CN ENERGY GROUP. INC.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

FORM 20-F

☐ REGISTRATION STATEMENT PURSUANT TO SECTION 12(b) OR (g) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

For the fiscal year ended September 30, 2025

OR

☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

OR

☐ SHELL COMPANY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

Date of event requiring this shell company report

For the transition period from to

Commission file number:001-39978

CN ENERGY GROUP. INC.

(Exact name of Registrant as specified in its charter)

N/A

(Translation of Registrant’s name into English)

British Virgin Islands

(Jurisdiction of incorporation or organization)

Building 2‑B, Room 206, No. 268 Shiniu Road

Liandu District, Lishui City, Zhejiang Province

The People’s Republic of China(Address of principal executive offices)

Jinwu Huang, Chief Financial Officer

Telephone: + 86‑571‑87555823

Email: jinwuhuang@cneny.com

At the address of the Company set forth above

(Name, Telephone, E-mail and/or Facsimile number and Address of Company Contact Person)

Securities registered or to be registered pursuant to Section 12(b) of the Act.

Securities registered or to be registered pursuant to Section 12(g) of the Act.

None

(Title of Class)

Securities for which there is a reporting obligation pursuant to Section 15(d) of the Act.

None

(Title of Class)

Indicate the number of outstanding shares of each of the issuer’s classes of capital or common stock as of the close of the period covered by the annual report.

An aggregate of 4,988,337 Class A ordinary shares and 635,419 Class B ordinary shares, no par value, as of September 30, 2025.

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.

Yes ☐No ☒

If this report is an annual or transition report, indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934.

Yes ☐No ☒

Note - Checking the box above will not relieve any registrant required to file reports pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 from their obligations under those Sections.

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.

Yes ☒ No ☐

Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such files).

Yes ☒ No ☐

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, or an emerging growth company. See definition of “large accelerated filer,” “accelerated filer,” and “emerging growth company” in Rule 12b‑2 of the Exchange Act.

If an emerging growth company that prepares its financial statements in accordance with U.S. GAAP, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐

Indicate by check mark whether the registrant has filed a report on and attestation to its management’s assessment of the effectiveness of its internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act (15 U.S.C. 7262(b)) by the registered public accounting firm that prepared or issued its audit report.☐

If securities are registered pursuant to Section 12(b) of the Act, indicate by check mark whether the financial statements of the registrant included in the filing reflect the correction of an error to previously issued financial statements. ☐

Indicate by check mark whether any of those error corrections are restatements that required a recovery analysis of incentive- based compensation received by any of the registrant’s executive officers during the relevant recovery period pursuant to §240.10D-1(b). ☐

Indicate by check mark which basis of accounting the registrant has used to prepare the financial statements included in this filing:

If this is an annual report, indicate by check mark whether the registrant is a shell company (as defined in Rule 12b‑2 of the Exchange Act). Yes☐ No ☒

TABLE OF CONTENTS

INTRODUCTION

In this annual report on Form 20‑F, unless the context otherwise requires, references to:

This annual report on Form 20‑F includes our audited consolidated financial statements for the fiscal years ended September 30, 2025, 2024, and 2023. In this annual report, we refer to assets, obligations, commitments, and liabilities in our consolidated financial statements in United States dollars. These dollar references are based on the exchange rate of RMB to United States dollars, determined as of a specific date or for a specific period. Changes in the exchange rate will affect the amount of our obligations and the value of our assets in terms of United States dollars which may result in an increase or decrease in the amount of our obligations and the value of our assets.

This annual report contains translations of certain RMB amounts into U.S. dollars at specified rates. Unless otherwise stated, the following exchange rates are used in this annual report:

FORWARD LOOKING STATEMENT

This annual report contains forward-looking statements that reflect our current expectations and views of future events. These forward-looking statements are made under the “safe harbor” provision under Section 27A of the Securities Act of 1933, as amended (the “Securities Act”), and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and as defined in the Private Securities Litigation Reform Act of 1995. These statements involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. All statements other than statements of historical fact in this annual report constitute forward-looking statements. We have used words or phrases such as “may,” “would,” “will,” “expect,” “anticipate,” “intend,” “seek,” “estimate,” “plan,” “believe,” “is/are likely to” or other similar expressions in this annual report to identify some of these forward-looking statements. These forward-looking statements, including, among others, those relating to our future business prospects, product development, revenues, profits, costs, capital expenditures, cash flows and working capital, are necessarily estimates reflecting the best judgment of directors and management and involve a number of risks and uncertainties that could cause actual results to differ materially from those suggested by the forward-looking statements. As a consequence, these forward-looking statements should be considered in light of various important factors, including those set forth in this annual report.

These statements involve risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from the information expressed or implied by these forward-looking statements. Although we believe that we have a reasonable basis for each forward-looking statement contained in this annual report, we caution you that these statements are based on a combination of facts and factors currently known by us and our projections of the future, about which we cannot be certain. Forward-looking statements in this annual report include, but are not limited to, statements about:

You should read this annual report, including the risk factors disclosed in “Item 3. Key Information-D. Risk Factors” and the documents that we refer to in this annual report thoroughly and with the understanding that our actual future results may be materially different from and worse than what we expect. Moreover, we operate in an evolving environment. New risk factors and uncertainties emerge from time to time and it is not possible for our management to predict all risk factors and uncertainties, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements. We qualify all of our forward-looking statements by these cautionary statements.

Market data and certain industry forecasts used in this annual report were obtained from internal surveys, market research, publicly available information and industry publications. Industry publications generally state that the information contained therein has been obtained from sources believed to be reliable, but that the accuracy and completeness of such information is not guaranteed. Similarly, internal surveys, industry forecasts and market research, while believed to be reliable, have not been independently verified, and we make no representation as to the accuracy of such information.

You should not rely upon forward-looking statements as predictions of future events. The forward-looking statements made in this annual report relate only to events or information as of the date on which the statements are made in this annual report. We undertake no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events.

The forward-looking statements made in this annual report relate only to events or information as of the date on which the statements are made in this annual report. Except as required by law, we undertake no obligation to update or revise publicly any forward-looking statements, whether as a result of new information, future events or otherwise, after the date on which the statements are made or to reflect the occurrence of unanticipated events. You should read this annual report and the documents that we refer to in this annual report and have filed as exhibits to the registration statement, of which this annual report is a part, completely and with the understanding that our actual future results may be materially different from what we expect.