Patent pledge financing revitalizes the value of intellectual property and provides financial support for enterprise innovation， thereby playing an important role in promoting the commercialization of technological achievements and stimulating firms’innovation vitality. Taking the patent pledge pilot policy as an exogenous shock， this paper systematically examines the impact of patent pledge financing on enterprise innovation based on a dynamic difference-in-differences model. The results show that patent pledge financing significantly improves firms’ overall innovation and substantive innovation， while having no significant effect on strategic innovation. This effect is more pronounced in industries with intense market competition，and varies substantially across firms with different ownership structures and sizes. In particular， non-state-owned enterprises and small and medium-sized enterprises respond more strongly to the policy. At the regional level， the implementation effect of the patent pledge policy is more significant when firms are located in eastern China and when the regional banking system is dominated by small and medium-sized banks. Mechanism analysis shows that patent pledge financing promotes high-quality innovation mainly by reducing firms’ debt financing costs， improving operational efficiency， and alleviating business risks. Further analysis indicates that financing constraints， financial supply capacity， and quality signal transmission are important moderating factors in promoting substantive innovation. This paper verifies the effectiveness of the patent pledge pilot policy oriented toward innovation quality， provides empirical evidence for optimizing technology finance instruments and improving the intellectual property pledge financing system， and offers important implications for directing financial resources toward enterprise innovation and promoting high-quality economic development in China.