Social organizations are important entities in the modernization of grassroots governance. Existing research mostly focuses on the government’s resource output and policy support for social welfare organizations, and there is a lack of discussion on the phenomenon of social welfare organizations feeding back to grassroots governments through multiple paths. Through a case study of the “Community Welfare Elderly Care” project empowered by Organization Z, this paper shows that the empowerment of grassroots governance by social organizations mainly includes structural empowerment, which promotes the formation of multiple subjects in grassroots governance, innovation of institutional mechanisms, and the broadening of government-citizen interaction channels; resource empowerment, which assists in solving difficult problems in the community; and psychological empowerment, which stimulates community vitality. The multiple empowerments of social organizations promote the multi-governance, vitality, stability, and orderliness of grassroots social governance, which has positive reference significance for social organizations to effectively participate in grassroots social governance.