Based on the regional social and economic statistics of the Lushui River main stream in Zhuzhou from 2012 to 2020, the TP discharge data were calculated and verified by the method of pollutant discharge coefficient, and the spatial and temporal characteristics of TP discharge from each source were analyzed. The results showed that TP discharge in the Lushui River main stream were 605.7-749.7 t from 2012 to 2020. TP discharge from agricultural source(396.71-535.25 t) was the highest, followed by domestic source(195.04-216.82 t). Swine breeding(30.4%-36.5%) and urban domestic source(16.6%-21.2%) accounted for a relatively high proportion of TP discharge, while industrial source contributed the least(0.2%-0.4%). Due to the large number of resident population and the fact that agricultural activities were dominated by farming and breeding, TP discharge of all pollution sources in Liling were higher than those in Lukou. Comprehensive discharge source data suggested that the Lushui River main stream should continue to strengthen the regulation and monitoring of discharge sources, especially domestic sources and livestock farming, and realize the source reduction of TP in an all-round way by promoting soil testing and formula fertilization, optimizing manure treatment technology and improving sewage treatment technology.