This paper discusses whether the audit firm size will be one of the important factors affecting the accounting policy disclosure behavior of listed firms by calculating the degree of “standardlike” of accounting policy disclosed in annual reports. The findings are as follows: (1) The accounting policy disclosed in the reports of companies audited by largesize audit firms are less “standardlike”, which will provide more personalized information about the accounting policy of the companies. (2) The relationship between the audit firm size and the degree of “standardlike” of accounting policy in annual reports will be strengthened when the risk of the firm rises or when the accounting standards change significantly, indicating that the risk pressure and the ability of audit firm are important influence paths. (3) Further research finds that the degree of “standardlike” of accounting policy in annual reports of companies audited by the same audit firm is more consistent with each other. (4) In the robustness test, the result is also consistent with the main hypothesis when the audit firm changes, which means that the degree of “standardlike” of accounting policy will be reduced if the size of the changed audit firm is larger, and will increase if the size of the changed audit firm is smaller.