Abstract: To evaluate the mechanism by which the First Secretaries stationed in villages impact the development of the new rural collective economy, based on a field survey of 17 villages in Jiangsu Province where First Secretaries are stationed, this study focuses on examining the influence of variables such as the effort level of the First Secretaries, introduction of new projects, contributions to infrastructure, village organizational communication and development, and social capital. The research employed a questionnaire survey method, collecting evaluation data from 269 villagers, and conducted empirical tests. The results indicate that the effort level of the First Secretaries has a significant positive impact on the development of the new rural collective economy. It not only directly promotes infrastructure improvement and the introduction of new assistance projects but also indirectly fosters the diversification and sustainable development of the collective economy by strengthening village organizational development and leveraging social capital. Based on the above findings, it is recommended to further optimize the selection and training mechanisms for First Secretaries, encourage them to introduce new technologies and projects tailored to local conditions, enhance village organizational communication and development, and fully utilize the social capital of the First Secretaries to improve the overall effectiveness of the assistance work.