The Hebei provincial government actively supports the participation of social capital in the construction of public projects, but there are significant differences among prefecture-level cities, mainly due to the influence of business environment factors. By collecting the business environment data of 11 prefecture-level cities, fuzzy sets qualitative comparative analysis (fsQCA) method was used to integrate seven anthems from the three levels of government, market, legal and policy environment, and explore the influence of the combination of factors on social capital’s participation in public project construction. It is found that the combination of these factors significantly affects social capital participation. The research conclusion shows that it is recommended that local governments strengthen the financial support for social capital to participate in public projects, and ensure the operation of project funds by broadening the sources of funds, strengthening supervision, personalized policy support and cooperation with financial institutions. At the same time, it is also necessary to pay attention to the boundaries of government supervision, avoid excessive market decision-making, and give social capital a certain degree of discretion.