How to improve the information content of key audit matters and enhance the relevance of audit report decision making has always been a key concern of the audit academic community. As an important part of the supervision system of the Party and the State, accounting supervision plays an important role in improving the quality of accounting information and maintaining financial order. Based on this, this paper examines whether government accounting supervision can improve the information content of key audit matters. It is found that government financial supervision can reduce the template disclosure of key audit matters and improve the information content. The mechanism test shows that the government’s financial supervision can improve the information content of key audit matters by increasing the auditor’s risk perception and the degree of diligence of the internal audit Committee. Heterogeneity test shows that when the enterprise has internal control defects and the risk of default is high, the government financial supervision plays a more significant role in improving the information content of key audit matters. Further research shows that government accounting supervision can reduce the text similarity of key audit matters. This reduction is observed when comparing matters audited under goverment supervision to those audited by different auounting firms, within the same industry and the same company from the previous year. In addition, the random sampling of accounting information quality of the Ministry of Finance and the normalized accounting supervision can form a synergistic effect and further enhance the information content of key audit matters.