The Twentieth National Congress of the Communist Party of China put forward that we should improve the mechanism of grassroots mass autonomy under the leadership of grassroots CPC organizations, strengthen the construction of grassroots organizations, improve the system of direct democracy at the grassroots level, and enhance the effectiveness of self-management, self-service, self-education and self-supervision. Mass participation is an indispensable part of social governance at the grassroots level. Especially in the new era of Chinese-style modernization, the practical content and social significance of mass participation are increasingly concerned and valued. By summing up the theoretical basis, institutional changes and practical experience of mass participation in grassroots social governance, this study comprehensively analyzes the characteristics of the mass participation in grassroots social governance, and then divides it into four modes: CPC leading guidance, independent participation, democratic consultation and pluralistic integration. Finally, to solve the problems in grassroots social governance, we should constantly improve the grassroots social governance system, improve the coordination mechanism of grassroots social governance, and enhance theability of the mass to participate in governance, so to achieve Chinese path to modernization of grassroots social governance.