This article is based on the RCEP Service Specific Commitment Table, and quantitatively evaluates the breadth of RCEP service trade openness by measuring the proportion of service sector openness and commitment coverage in the agreement. By using the extended Hoekman frequency method, the depth of RCEP service trade openness is calculated. And using the depth index as the Ams shock variable, the GTAP model was used to empirically analyze the impact of RCEP service trade openness on China. The results indicate that the breadth and depth of RCEP’s service trade openness are relatively high; China’s level of openness in service trade ranks upstream, but there is still a significant gap compared to developed countries; The analysis results of the GTAP model found that RCEP has a significant driving effect on the development of China’s service trade, not only increasing the scale and sectoral output of service trade imports and exports, but also improving the previous service trade deficit and structural irrationality in China; With the implementation of the negative list in China and the deepening of the openness of service trade in various countries, the role of RCEP in promoting China’s service trade will be strengthened.