The construction of water conservancy and hydropower project may have effect on migrants' lifestyle, social interaction and social psychology, infrastructure and public facilities, social networks, income and expenditure, employment and livelihood patterns. With the change of development concept and resettlement ideas, the improvement of resettlement policy, the innovation of resettlement model, the impact of project construction on the social system of resettlement has gradually been avoid and reduced, but it can not be completely eliminated. In order to realize the recovery and reconstruction of resettlement social systems, it is necessary to optimize the selection of resettlement sites and the implementation of external aid and internal intervention. Also, employment service should be provided, migrants' work capability should be redeveloped, resource inclination and integration should be strengthened and resettlement institution should be emphasized. Then it is possible to reconstruct the social system of resettlement.