The smooth integration of urban migrant workers is important in transforming economic development mode, in accelerating urbanization and in constructing socialist harmonious society. Migrant workers have such developing troubles as survival, mental, occupational, social and political confusion, but city integration self is important value orientation and ultimate goal of solve the integration dilemma. After discussing the rule and direction, we definitude that the essence of city integration of migrant workers would be city sub cultural identity and that the key would be psychological reconstruction which would be adapt the way of city life and production, thinking and social customs and habits and so on in order to help migrant workers walk out the dilemma of city integration.