Taking A+H shares which disclose key audit items in the annual report of 2016 and A-share listed companies in the annual report of 2017-2018 as the research objects， we use the intermediary effect test method， it is found that when the risk of enterprise litigation is high， auditors will choose to disclose more key audit items， which leads to the increase of audit fees. Further tests show that only in the groups with high risk-taking level， high earnings management level and high ownership concentration， disclosure of key audit items play an intermediary role between litigation risk and audit fees. This paper examines the relationship between corporate litigation risk and audit fees from a new perspective of key audit matters， and clarifies the mechanism of the impact of corporate litigation risk on audit fees， that is， the role of disclosure of key audit matters as an intermediary variable of corporate litigation risk affecting audit fees in risk disclosure.