In recent years, China's innovation has entered a new stage of development from "quantity" to "quality", and the supply side policies supporting innovation are weak. How to better play the role of the "new carriage" of demand side government procurement policies has become an increasingly concerned issue in all sectors of society. Using data from 3633 Shanghai and Shenzhen A-share listed companies from 2015 to 2021, along with 11887 government procurement contract records and over 1.34 million patent data entries, the enhancing effect and influencing mechanisms of government procurement on corporate innovation quality were empirically examined. The findings indicate that government procurement significantly promotes the improvement of innovation quality in enterprises, and significantly enhances the innovation quality of enterprises through two mechanisms: expanding market demand and alleviating financing constraints. Heterogeneity analysis shows that government procurement can better promote the improvement of innovation quality in small and medium-sized enterprises, non-state-owned enterprises, and strategic emerging industry enterprises. Based on these results, it is recommended that China further refine its government procurement policies and implementation plans, enhance their adaptability, and promote high-quality innovation and development among enterprises.