Green technology innovation (GTI) is an effective way to promote the green development of economy, and government environmental regulations are an important means to encourage enterprises to carry out GTI. Taking Chinese A-share listed enterprises from 2010 to 2019 as samples, this paper divides environmental regulations into three categories: command-based environmental regulation (ER), market-based environmental regulation (ER) and voluntary environmental regulation (ER), studies their impact on enterprise GTI, and discusses the joint effect of enterprise research and development (R&D) investment and government support from the perspective of internal and external linkage of enterprises. In addition, this paper also analyzes the compound effect and time effect of environmental regulation. The research conclusions are as follows: (1) From the perspective of policy types, both ER and ER could stimulate enterprises to carry out GTI, and the promotion effect of green utility model patents is slightly higher than that of green invention patents. ER inhibits enterprise GTI. In addition, this paper finds that the effect of three environmental regulations acting at the same time is greater than that of one of them. (2) The mechanism analysis shows that the R&D investment of enterprise positively could moderate the relationship between ER and green invention at the significance level of 5%, positively moderate the relationship between ER and green utility model patent at the significance level of 1%, and negatively moderate the relationship between ER and green utility model patent at the significance level of 5%. The government support could moderate the relationship between environmental regulation and green utility model patents at the significance level of 5% and 10%. (3) The effect analysis shows that the transformation rate of GTI in China needs to be improved. The three environmental regulations could have an effect on enterprise GTI in a short period, and ER has the fastest effect. (4) Considering the differences in the level of economic development and resource endowments in various regions of China, this paper classifies the sample enterprises and finds that the impact of environmental regulation on enterprise GTI is heterogeneous in terms of location, ownership nature, factor density and industry type. The research results provide the important reference for the formulation and implementation of environmental regulation policies according to local conditions.