Abstract: In order to fully understand the current situation of livestock and poultry farming pollution and its potential impacts on the ecological environment, the potential of livestock and poultry manure as a substitute for chemical fertilizers was analyzed in the water source area of the middle route of the South-to-North Water Diversion Project. The environmental risk assessment model was used to quantitatively analyze the main manure source structure of each county (city, district) in 2022 based on the data of 49 county-level livestock and poultry farming information and cultivated land area. Total nutrient content and alternative potential of livestock and poultry manure of different animal species and in different regions were estimated. The results showed that the total amount of livestock and poultry manure was 1 534.024×10⁴ t, and the distribution was relatively concentrated. The amount of chemical oxygen demand (COD) was the highest (199.416×10⁴ t), followed by total nitrogen (TN, 8.600×10⁴ t), and total phosphorus (TP) was the least (1.767×10⁴ t). 18.37% of the counties (cities, districts) in the water source area had potential environmental risk of pollution from livestock and poultry farming, among which Danfeng County was at relative severe risk; Neixiang County and Maojian District were at risk; Dengzhou City, Danjiangkou City, Yunyang District, Xunyang County, Shanyang County, and Wanyuan City were at a little risk; and the rest were at no risk. The load of animal mnaure per hectare of cultivated land in the water source area was 9.235 t hm⁻², the alarm value was 0.308, and the grade index was Ⅰ. The total equivalent standard pollution load was 48.165×10¹⁰ m³. The source structure of pollution was inconsistent in different regions. TP was the primary pollutant in livestock and poultry farming, and its equivalent standard pollution load accounted for 36.69% of the total load, followed by TN with equivalent standard pollution load rate at 35.71%, and COD with the lowest equivalent standard pollution load rate at 27.60%. Pollution from livestock and poultry farming in the water source area mainly originated from pig and cattle, who contributed to 47.90% and 41.77% of the total equivalent standard pollution load, respectively. The total nutrient resources in manure in the water source was 21.195×10⁴ t, and the theoretical potential for fertilizer alternative was 20.67%. According to the theory of nutrient resources for different livestock and poultry manures, the potential of cattle manure, pig manure, poultry manure, and sheep manure to replace chemical fertilizer were 8.86%, 6.50%, 3.05%, and 2.26%. The theoretical potential of nitrogen, phosphorus, and potassium in livestock and poultry manure to replace chemical fertilizer were 16.77%, 6.89%, and 42.23%, respectively. It is of great significance to control the total livestock and poultry farming in potential risk areas, promote structural adjustment in different counties, and realize the resource utilization of livestock and poultry manure instead of fertilizer to promote the green development of breeding industry in middle route of the South-to-North Water Diversion Project water source areas.