Abstract:Based on the perspective of mediating effect of auditing expectation gap, the paper explores the way that the peer effect influence the companies green innovation decisions. Through the data analysis of A stock market companies from the year 2009 to 2019, we discovered the peer effect plays the key role in improving the green innovation decisions and the auditing expectation gap plays the partial mediation effect between the peer effect and the green innovation decisions. While the market uncertainty and environmental regulation plays the positive moderation effect on the relationship between auditing expectation gap and companies green innovation decisions. From the perspective of auditing expectation gap, we can explain how does the peer effect and group decisions affect the individual company’s green innovations, which is beneficial to make the environmental and industrial regulations for the government and companies strategies decision.