Based on the economic theory of supply school and the actual situation in China, this paper analyzes the relationship and countermeasures of supply-side structural reforms, easing corporate financing constraints, and improving corporate innovation capabilities. Firstly, the theory of supply school is used to analyze the boundary and focus of supply-side structural reform; secondly, it discusses the embeddedness and coupling between supply-side structural reform, financing constraints, and corporate innovation; Finally, from the three levels of government, enterprises and social institutions, strategies and suggestions for further advancing supply-side structural reforms, easing corporate financing constraints, and improving corporate innovation capabilities are proposed.