The purpose of communicating key audit matters in audit report is to open the “black box” of audit activities and provide more information to report users. This paper examines the impact of audit report information content on stock price crash risk by using text analysis methods to construct an industry text similarity measure of key audit matters for a sample of A-share listed companies from 2016-2021. It is found that the industry text similarity measure of key audit matters is significantly and positively related to the company’s future stock price crash risk. The lower the audit report information content, the higher the company’s future stock price crash risk, and this finding still holds after a series of robustness tests. Further research finds that high corporate governance level and good information supply and demand can significantly restrain the effect of insufficient information content of audit report on stock price crash risk. This paper deepens the research on CPA audit and capital market, and puts forward suggestions from three aspects of audit supply, audit demand and audit supervision to promote the stable and high-quality development of capital market.