Abstract: The effective integration of rural innovation and entrepreneurship is a key pathway to promoting high-quality development of county-level economies. Based on panel data from counties in Shaanxi Province from 2014 to 2022 and the Agricultural Innovation Index, which was released in 2024 by the ZJU-CARD Enterprise Research Team for Rural Industries, a two-way fixed effects model is employed to systematically analyze the influence of rural innovation and entrepreneurship on county-level economy and its mechanisms. The results show that rural innovation and entrepreneurship significantly promote high-quality economic development at the county level. Mechanism analysis reveals that rural innovation and entrepreneurship primarily drive economic growth by facilitating local industrial structure upgrading. Heterogeneity analysis shows that rural innovation and entrepreneurship have a more pronounced effect on economic development in southern Shaanxi, central Shaanxi, and counties with weaker industrial foundations. Moreover, the promoting effect of traditional financial support on county-level economies is stronger than that of digital inclusive finance. Government intervention exhibits a threshold effect. When the level of government involvement exceeds a specific threshold (0.101), the promoting effect of rural innovation and entrepreneurship on county-level economy increases substantially. Based on these findings, policy recommendations are proposed, including optimizing the innovation and entrepreneurship environment, enhancing financial support, guiding industrial innovation according to local conditions and strengthening talent cultivation and recruitment.