Based on the statistical yearbook data and related patent data of 287 cities in China from 2000 to 2020, this study regards the policy of establishing the national high-tech zones as a quasi-natural experiment. Using this experiment, this study firstly estimated the treatment effect of the policy and checked the robustness of the estimation. Then the study examined the heterogeneity in different geographic demarcation of China and in different city level of China. After that, this study explored the possible influence mechanism of the policy. It shows that the possible mechanism of the policy is financial support, industrial agglomeration of secondary industry and the spillovers. In the end, this study examined the spillovers deeply and showed the distribution of spillover effect.