In practice,the social relevance,interest related and elite income in the autonomous unit are the three social dynamic mechanism of villager autonomy,which determine the effect of villager autonomy. In the practice of double deck villager autonomy in Zigui County of Hubei Province,the social dynamic mechanism has played different roles in administrative villages and villages. Villages,compared with administrative villages,could better preserve community memory and establish modern social connections. In terms of public goods supply,land property right and industrial development,it is difficult for administrative villages to form consistent interests,while villages have high homogeneity interests; The administrative village cadres do not care about social benefits such as face and authority in villages,but care about the economic benefits from county and township,but the village cadres need social benefits such as face,reputation,authority,and economic benefits such as the subsistence allowances. Three bottom-up social motive mechanism is more powerful in prompting villager autonomy of the village. Village autonomy can play a better role in the governance function of grassroots democracy in the village autonomous unit. Therefore,the villager autonomy should be adapted to the social foundations of the village.