As an important way to obtain digital technology and data resources, digital mergers and acquisitions have the value of digital innovation and corresponding risks, which will have an impact on audit work. This paper selects the merger and acquisition events of non-financial listed companies in China's A-share market from 2009 to 2022 as samples, and uses audit fees as the starting point to empirically test how digital mergers and acquisitions affect audit work and pricing decisions. The results show that the digital M&A of the auditee significantly increases the audit cost, which is still significant after considering the endogenous and robustness issues, which means that the digital M&A of the auditee may increase the auditor's perceived audit risk and increase the audit cost. Mechanism testing found that digital M&A significantly increase the inherent and control risk of the audited entity, and auditors will correspondingly increase their audit investment, thereby affecting audit pricing decisions. Heterogeneity testing found that when the audited entity is a digital economy enterprise, the executive team has a digital background, hires international “Big Four” accounting firms for auditing, and has high expertise in the certified public accountant industry, the positive impact of digital M&A on audit fees is not significant. This paper explores the “other side” of enterprise digital development from the perspective of audit fees, improves the research on the risk and cost of digital M&A, and enriches the innovative research of the current audit system in the new digital context.