Abstract: The quality of patents to a certain extent determines the size of financing costs for enterprises, and it is necessary to further explore the relationship between the two. This article explores the impact of patent quality on equity financing costs and debt financing costs, and further analyzes the mediating role of active patent litigation and patent pledge risks. The research results indicate that improving patent quality has a significant promoting effect on reducing the cost of equity financing and debt financing for enterprises. The mechanism test results indicate that on the one hand, enterprises can increase the probability of active patent litigation and reduce equity financing costs by improving patent quality. On the other hand, enterprises can reduce the risk of patent pledge financing and lower debt financing costs by improving patent quality. Heterogeneity testing shows that compared to growth stage enterprises, improving patent quality can more effectively reduce the equity financing costs of mature enterprises, but its impact on debt financing costs is lower than that of growth stage enterprises. In addition, compared to imitative enterprises, improving patent quality can better reduce the equity and debt financing costs of innovative enterprises. Finally, this article proposes relevant suggestions for reducing corporate financing costs from three aspects: patent information disclosure, patent litigation, and patent pledge.