An urban reclaimed water project adopts the mode of government and social capital cooperation, which can alleviate a shortage in capital and allow for the inclusion of advanced management experience. Thus, introducing the best partner is an important precondition for successful implementation of a PPP(public-private-partnership)project. In this study, the partners participating in the competition were selected and an evaluation index system, which included a criterion layer consisting of the indices of company size, financial level, technical ability, credit level, and management ability, as well as an index layer consisting of 24 specific terms, based on the characteristics of the urban reclaimed water project, was established. The grey correlation evaluation method was used to comprehensively evaluate the indices of different layers. The subjective weighted AHP method and the objective weighted entropy method were jointly used to determine the weights, in order to select the best social capital partner and help the government make better decisions.