Based on the institutional background of the implementation of the Guiding Opinions on the Pilot Implementation of ESOP by listed companies issued by China Securities Regulatory Commission in June 2014, this paper takes the listed companies that implement ESOP from 2014 to 2017 as the research object, and uses PSM method to empirically analyze the mechanism of ESOP influencing the effectiveness of internal control. The study finds that the implementation of ESOP can significantly improve the effectiveness of internal control; the three elements of internal supervision, information and communication and control activities have intermediary effects; ESOP mainly improves the effectiveness of internal control by strengthening internal supervision, improving information and communication, and optimizing control activities; At the same time, equity concentration degree has a moderating effect, and low ownership concentration can strengthen the promotion effect of ESOP on the effectiveness of internal control. This study provides important policy implications on how to improve the effectiveness of internal control through the implementation of ESOP.