After the baptism of urbanization and modernization， returning rural migrants have unique advantages in promoting economic development， disseminating advanced culture and facilitating rural governance. Clarifying the behavioral logic of returning rural migrants’ participation in rural construction is of great significance in addressing the challenges of the lack of farmers’ subjectivity in rural construction and alleviating the talent constraints faced by rural revitalization. Based on data from surveys of returning rural migrants from four provinces， namely Hubei， Hunan， Guizhou and Sichuan provinces， this paper uses negative binomial regression model and mechanism analysis model to examine the influence of social capital such as social networks and social trust on the participation of returning rural migrant in rural construction and its mechanism. The results indicate that， first of all， the level of participation of returning rural migrants in rural construction is relatively low， with nearly 30% of them having never participated in public affairs in their own villages. Formal networks， informal networks and institutional trust have positive effects on promoting the participation of returned rural migrants in rural construction， with obvious characteristics of “organizational mobilization” and “institutional guidance”. Secondly， further mechanism analysis reveals that formal networks， informal networks and institutional trust promote the participation of returning rural migrants in rural construction by enhancing their village identity. The elevation of subjective consciousness has significantly weakened the role of formal networks and institutional trust in mobilizing and guiding the participation of returning rural migrants in rural construction， while the expression of subjective values based on the action meaning dominates the relationship. Meanwhile， a strong sense of subjectivity is also an important condition for interpersonal trust to facilitate the participation of returning rural migrants in rural construction.