M&A is an important approach to promote the development of creative economy and mixed ownership reform of state-owned enterprises. From the Board Functions Perspective, this paper explores the influence reputation mechanism of interlocking directorates on firms' M&A performance, using event study, BHAR model and nonparametric tests. We find that high reputation has a significant and positive effect on M&A performance mainly by improving advisory service of interlocking directorates and reducing asymmetric information. Furthermore, this effect is more significant when the target company's accounting information is more opaque or M&A behavior occurs in different places. However, in a company which has a serious agency problem, interlocking directorates can't play a supervisory role to improve the M&A performance. Even interlocking directorates that possess a low reputation may seize personal interests with management group and damage the value of M&As. The results of this paper show that improvement of the positive effect of interlocking directorates on M&A performance should be based on strengthening of director's reputation mechanism and improving corporate governance.