Based on the basic situation in Beijing，the paper studies the current situation of the integration of mixed community of commercial housing and affordable housing in Beijing through questionnaires and interviews，and selects the typical mixed community in Fengtai District and Chaoyang District of Beijing as the survey object in order that we can deeply restores the related events and controversy of the conflicts occurred in the typical mixed community in 2017. And diagnose the status quo of the neighborhood relationship and integration between the commercial housing owners and affordable housing owners in mixed community in Beijing. The study found that mixed community with affordable housing construction in Beijing has problems such as weak neighboring relationship，low level of resident satisfaction，difficulty in community integration，and poor community stability. The study believes that the construction planning policy is the root cause of the contradictions and conflicts between the two owners，and leads to negative effects such as the degradation of social capital in the community，the deterioration of the community resources and environment，the long-term vacuum of community relations，the increase in the cost of living for affordable housing owners，and discrimination and hateful attitudes towards commercial housing owners due to the economic disparity，which in turn become factors that hinder the integration of residents in the mixed community. In the end，the paper rethinks the planning policy of Chinese affordable housing supply and proposes the optimum suggestions for affordable housing supply in Beijing，and proposes corresponding suggestions and solutions for solving the historical problems of the contradiction between the social stratum in mixed community in Beijing.