Enterprises use complex conduit business financing to conceal their actual liability levels, which not only reduces the quality of accounting information, but also leads to a serious underestimation of the leverage ratio of the real economy, thus becoming a potential crisis affecting the stable development of micro enterprises and macro economy. Using the exogenous shock of “de-conduit” in the New Rules on Assets Management (NRAM), this paper examines the impact of conduit business regulation on audit pricing. The results show that after the promulgation of the NRAM, the audit fees paid by enterprises that previously used conduit financing have significantly decreased. Heterogeneity analysis reveals that when enterprises are more inclined to conceal liabilities and evade regulation, and when auditors’ professional abilities are insufficient, conduit business regulation has a greater impact on audit fees. Mechanism testing reveals that conduit business regulation leads to a decline in audit fees by reducing audit risks and audit costs. This paper uncovers the positive role of financial regulation in improving the quality of accounting information, and has important implications and practical significance for regulatory agencies, auditors, and corporate decision-making.