We studied the impact of agricultural non-point source pollution on the water quality of Luochang River, analyzed the main sources of pollution such as fertilizer loss, pesticide residues, and livestock and poultry breeding waste, and explored the transmission pathways of pollutants and their specific effects on water quality. Through real-time monitoring and data analysis, it was found that agricultural non-point source pollution significantly affects the water quality of the Luochang River, especially contributing significantly to the total nitrogen concentration. Based on this, measures have been proposed to promote scientific fertilization, green prevention and control technologies, strengthen the management of livestock and poultry breeding waste, and promote the resource utilization of agricultural waste. The research results indicate that these scientific prevention and control measures are of great significance in reducing agricultural non-point source pollution and protecting the water quality of the Luochang River, providing theoretical basis and practical guidance for achieving ecological balance and sustainable development in the basin.