As a kind of renewable energy, biomass power has great development potential in mitigating greenhouse gas emissions. Therefore, under the background of carbon peak and carbon neutrality, the diffusion of biomass power generation technology has practical significance. To address these issues, this paper constructs a system dynamics model to study the impact of different policy effects on the diffusion of biomass power generation technologies. The results show that the feed-in tariff policy can significantly promote the installed capacity growth of biomass power generation projects; on the other hand, carbon emission trading increases the investment value of projects and promotes the growth of the installed capacity of biomass power generation projects, to a certain extent, so relevant policies need to be improved to achieve the promotion of biomass power generation technology in the future.