Abstract: Comparing the design and practice of the social governance system of the unit system period with the new era, this paper demonstrates the institutional confidence of the socialist system with Chinese characteristics through the methods of literature study and comparative research. The result shows that, on one hand, the advance of social governance system is based on the change of social principal contradiction; on the other hand, on the adherence to the party's leadership and "people-centered" in different periods. This conclusion provides theoretical and practical support for the institutional confidence of socialism with Chinese characteristics.