Abstract: In order to promote the modernization of national governance system and governance capacity, it is important to strengthen the system supply of the vertical governance between the central government and local governments. The implementation deviation of local governments has always been a big issue in China’s vertical governance. In tackling with this problem, the central government has largely increased the use of supervision system in the governance practice since the 18th CPC National Congress. However, few study explored the role, significance and operation mechanism of this system in vertical inter-governmental relationship. By examining the case of the central environmental protection supervision implementation in Zhejiang province, we found that the supervision system with the authority of the central government exerts the top-down high-intensity control, systematically embeds the governance system through the overall procedures of mobilization, implementation, feedback, rectification, accountability and follow-up re-examinations, reduces the information asymmetry, and corrects the target deviation. In this way, it effectively strengthens the effectiveness of implementation and improve the efficiency of vertical governance.