This paper takes listed companies from 2010 to 2019 as the sample to explore the impact of pricing deregulation in the audit market on audit efficiency and quality. The results show that audit efficiency (DEA) and audit quality (discretional accruals) are improved after audit pricing deregulation. After using Parallel Trend Test, replacing variable measurement, and adding market reaction, the results are still robust. Mechanism testing shows that increasing audit input, strengthening audit interview, and intensifying audit market competition are the three ways to improve audit efficiency and quality. Heterogeneity analysis finds that when the levels of marketization and the rule of law are low, as well as in state-owned enterprises and low-fee and fee-reduction audit firms, audit pricing deregulation has a more significant effect on the improvement of audit efficiency and quality. Pricing deregulation re-emphasizes the decisive role of the price mechanism in the allocation of factors and provides a theoretical basis and practical reference for continuing to deepen the reforms to streamline administration and delegate power, improve regulation, and upgrade services.