Since the reform and opening-up, China has developed into the world’s number one manufacturing country. Meanwhile, China’s environmental protection efforts continue to strengthen. So, will changes in the intensity of environmental regulatory policies have an impact on the technological development level and international competitiveness of China’s high-tech manufacturing industries? In response to this issue, we have reviewed relevant research in the field of environmental regulation and export technology complexity, and then selected appropriate indicators to quantify the environmental regulation and export technology complexity of high-tech manufacturing industries in different regions of China. Furthermore, the entropy method was used to calculate the intensity of environmental regulations in different regions of China. In the subsequent empirical analysis, based on relevant indicator data from 30 provinces in China, excluding Tibet, from 2006 to 2021, we quantitatively analyzed the impact of China’s environmental regulations on the complex export technology of high-tech manufacturing industries. The degree of influence and the robustness of the benchmark regression results was proved through endogeneity testing and robustness testing. The main conclusions are as follows: (1) from 2006 to 2021, China’s environmental regulation intensity and the technological complexity of high-tech industry exports have shown an upward trend. (2) The empirical analysis results show that the increase in intensity has a significant “U-shaped” impact on the technological complexity of exports of high-tech manufacturing industries. (3) The “U-shaped” impact of environmental regulation on the technological complexity of exports of high-tech manufacturing industries has regional differences. However, the high-tech manufacturing industry does not show obvious industry differences. (4) Environmental regulations will affect the level of export technology complexity of the high-tech manufacturing industry through foreign direct investment, human capital, and innovative R D investment, which cause indirect effects. Based on those conclusions, this paper has suggested corresponding policy measures and future research directions.