Domestic sewage is an important source of surface water pollution in the rural areas of developing countries, especially in the rural areas of China. In recent years, with the strategy of rural revitalization, China has paid increasing attention to the treatment of rural domestic sewage. Therefore, 16 villages in the Chengdu Plain were selected for the study, and seven indicators were analyzed and evaluated, including pH, five-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonia nitrogen (NH3-N), total phosphorus (TP), suspended solids (SS) and total nitrogen (TN), in the water samples at the inlet and outlet of the wastewater treatment plant. The concentration of each pollutant in the rural scattered domestic sewage of the Chengdu Plain in Southwest China was obtained, and the concentration of each pollutant in domestic sewage was higher than that in summer. In addition, the preferred process for removing each pollutant was obtained by studying the effects of the treatment process, season and hydraulic retention time on the removal efficiency of each pollutant. The research results provide valuable references for the planning and process selection of rural domestic sewage treatment.