Abstract:With the increase of regional urban population and the improvement of people's living standards, the environmental pollution problem of river water in Jianghuai hilly region has become increasingly prominent, which has become one of the main constraints of regional social and economic development. The paper takes the Macao River Basin located in the hilly region of Jianghuai as the research object, through data collection, questionnaire survey, field investigation and other means, to find out the main contributing factors and proportions of the pollutant indexes COD, NH3-N, TN, TP into the river in this region. Domestic pollution (51%, 40%, 54%, 28%), non-point source pollution (6%, 38%, 9%, 42%) and livestock and poultry farming (39%,15%, 17%, 25%) accounted for more than 90% of the total contribution, while endogenous pollution and aquaculture were less. According to the characteristics of the investigation results of pollution sources, some treatment suggestions are put forward, such as improving the pipe network in the town, decentralized treatment in rural areas, treatment of livestock and poultry manure, farmland absorption of breeding wastewater, setting up pollution buffer zones, interception and reuse of runoff, Ecological transformation of rivers and so on. It can provide experience for the investigation and treatment of pollution sources in small and medium-sized rivers in the future.