How to improve the effectiveness of the audit market has always been a hot spot in audit theory research. The effectiveness of the audit market is measured by the sensitivity of audit fees and risks. Selecting A-share listed companies in Shanghai and Shenzhen from 2010 to 2019 as a sample, this paper studies the impact of deregulation of audit service prices on the effectiveness of the audit market and the moderating effect of the scale of the accounting firm and the degree of marketization of the client’s location on the above relationship. The study finds that the deregulation of audit service price control has increased the overall audit fee risk sensitivity of accounting firms; compared with non-“top ten” firms, the domestic “top ten” firms are more sensitive to audit fee risks after deregulation of audit service price controls. If the customer’s location is highly market-oriented, the risk sensitivity of audit fees will increase significantly after the deregulation of audit service price control. After a placebo test, the conclusion is still valid.