Grassroots social governance is an important part of the national governance system. The improvement of its governance level and the innovation of governance model are of great significance for realizing the modernization of state governance. This paper expounds the basic characteristics of this model through the field investigation of the Three Lines And Two Platforms of Hanyin County in Shaanxi Province，and analyzes the actual results of this model in grassroots social governance. The empirical practices and innovative features of this model have important reference value for promoting grassroots social governance in our province.