The study finds that analyst skill plays a key factor to explain the complicated and chaotic relation between analyst coverage and external governance. We divide analysts into multiple skill groups by GMM (Gaussian mixture model) method, and explore the effect of the coverage by skilled analysts on earnings management in Chinese listed companies. The results indicate that only the coverage of skilled analysts shows a significant negative correlation with earnings management. Heterogeneity analysis reveals that the negative relationship between the coverage of skilled analysts and earnings management is primarily observed in non-state-owned companies, those with weaker external audits, and smaller-scale firms. The conclusion remains robust after considering endogeneity issues. The findings of this study suggest that incorporating analyst skill contributes to a better understanding of the mechanisms through which analysts influence corporate governance. It also highlights that the role of analysts in corporate governance cannot be generalized.