Abstract: With the development of the social economy, social problems are becoming increasingly prominent. Solving social problems only by the government and public welfare organizations is difficult. Social enterprises offer opportunities for sustainable solutions to social problems; however, social enterprises generally face the problem of poor performance. Although previous studies provide some clues on the impact of social relations on social enterprise performance, whether social relations impact performance remains unknown, and the mechanism remains unclear. Based on resource-based theory, our study proposes the role of business model innovation as the intervening mechanism. Market information management capability enhances the positive effect of social relations on business model innovation. The findings from a survey of 198 Chinese social enterprises show that social relations have a significant positive impact on economic performance and social performance and that business model innovation plays a mediating role between social relations and performance. Market information management capability plays a positive moderating role between social relations and business model innovation. The research results enrich the research on the influencing factors of social enterprise performance, reveal the influencing mechanism and boundary conditions of social relations on social enterprise performance, and propose effective practical measures for improving social enterprise performance.