Green technology innovation is the fundamental way to break the constraints of resources and environment. As a "soft constraint", public participation plays an increasingly prominent role in green technology innovation. Based on the unique advantages of the public to make up for "government failure" and "market failure", this paper systematically discusses the impact and transmission mechanism of public participation on green technology innovation, and makes an empirical test by using fixed effect model, intermediary effect model and spatial econometric model. The results show that: (1) public participation can significantly improve green process innovation, but has no obvious effect on green product innovation; (2) Public participation depends on government environmental regulation, which forces enterprises to internalize pollution costs, and then indirectly affects green process innovation; (3) In terms of regional heterogeneity, the effect of public participation on green process innovation is more obvious in economically developed areas; The positive effect of government environmental regulation on green process innovation or product innovation is more obvious in areas with high public participation; (4) In terms of spatial effect, local public participation will not only improve local green process innovation, but also radiate this positive effect to the surrounding areas with small economic gap. The research of this paper is conducive to clarify the impact of public participation on green technology innovation, clarify its action path, and provide reference for the effective implementation of the "tripartite governance" governance system.