The social relation net of family & pan-family plays an important role in entrepreneurship by rural migrant workers returned to hometown, and the integrality and unimpededness of the social net is essential to success of entrepreneurship. After studying the relationship between social capitals, social networks and entrepreneurship by rural migrant workers returned to hometown, this paper analyzes the value of social networks of rural migrant workers based on the entrepreneurial value of social networking elements. Then the condition of social network to support for migrant workers returning home business is given. Finally, the countermeasures based on self-building and to aids from the government to restructure the rural migrant workers' social net are also given in the end.