Using panel data from 31 provincial-level administrative regions in China from 2012 to 2021 as a research sample, this paper uses a dual difference model and an intermediary effect model to empirically test the impact of policy implementation effect audit on the high-quality development of manufacturing industry, based on the construction of an evaluation index system for high-quality development of the manufacturing industry. Research findings are as follows: (1) Policy implementation effect audit can significantly promote high-quality development of the manufacturing industry. (2) Digitization has a positive moderating effect on the impact of policy implementation audit on the high-quality development of the manufacturing industry. (3) Business environment is an intermediary factor in promoting the high-quality development of manufacturing industry through policy implementation effect audit, and plays a partial intermediary role. Therefore, we should promote the high-quality development of the manufacturing industry by improving the efficiency of audit supervision, enhancing the level of digitization, and improving the business environment.