Social capital is an integral part of farmers’ life, which can be exogenously affected by land recuperation. Based on 1240 farmer field survey data in Gansu Province, this paper used the Logit model to analyse the influencing factors of farmers’ participation in land recuperation, and used the entropy method to measure social capital from the three dimensions of social network, social trust and social norms, and further used the propensity matching score method to measure the effect of land recuperation on farmers, and then compared the effects under different fixed ages and education groups. The following factors significantly affected farmers’ participation in land recuperation: age, years of education, migrant workers’ relationships with family and friends, relationship between migrant workers and friends and colleagues in the workplace, number of migrant workers away from home, cultivated land area, and family living standards. Land recuperation had the greatest promotion effect on farmer’ social network (163.9%), followed by social trust (28.0%) and social norm (11.3%). According to the results of group differences, land recuperation most significantly affected the social capital of farmers aged 45–55 years and household heads educated for 9–12 years compared to other age and education groups.