Faced with the increasingly serious problems of water resources, "China's economic and social development Twelfth Five-Year Plan" proposed to promote energy saving and emission reduction, the technical transformation of domestic water, and the utilization of recycled water. According to this, the paper mainly studies the city residential sewage reuse. First it analyzes the situation of China's urban water resources and feasibility of urban residence sewage reuse. Then through investigation and study, it divides the domestic sewage into three categories: namely, high-quality sewage, medium-quality sewage, and low-quality sewage, and for different types of sewage are treated in different ways. Key part of this paper is the domestic sewage reuse system design, this design reflects the characteristics of effective use of sewage resources and reduce energy consumption, possesses the environmental utility of saving water, reducing pollution and wastewater emissions. The purpose of this paper is effective use of domestic sewage, so as to achieve the environmental and social usefulness of energy saving and emission reduction.