As an important component of project management, government service outsourcing plays an important incremental reform role in promoting and improving local governance innovation and governance capabilities. However, the current comparative study on the systems, models and structures of Chinese and foreign service outsourcing is rarely involved. Based on the institutional comparative analysis, this paper selects the Chinese and American government service outsourcing models for comparison, and analyzes them from the framework, elements and paths, and discusses the institutional model issues. The study found that the US government’s view of efficiency to the turn of public values is an important basis for a systematic, malleable and diverse service outsourcing system. There are major differences in the field of purchase, scale, method, allocation of funds, payment,purchase restrictions and supervision in the process of Sino-US service outsourcing policy. However, there are certain common problems in the interaction between government and society. It is necessary to promote the formation of “benign” interactions between government and society from outsourcing methods, process and supervision.