Through comprehensive monitoring and screening of toxic pollutants in the basin water system, a list of best controlled pollutants (27 types) in the Dongjiang water system based on risk assessment was obtained. It not only has national control indicators, but also contains a number of new pollutants, reflecting the Dongjiang River Basin pollution characteristics. Conducting forward-looking research on optimal pollutant risk management technology in the Dongjiang Basin, breaking through four key technologies: pollutant monitoring technology, risk assessment technology, source-sink simulation technology and optimal pollutant screening technology. Through technology integration, a complete set of water source river optimization control pollutant risk management technology system has been formed, and the "Dongjiang Basin Poisonous Pollutant Data Information System" has been built to apply it to chemical risk management in the Dongjiang Basin. Demonstration of the application of toxic pollutant analysis methods and monitoring technologies was carried out in the Dongjiang River Basin. The application demonstration units covered project engineering topics, local environmental monitoring stations in Dongguan, Huizhou, Heyuan, etc., and the Dongjiang Water Environment Research Center workstation. This technical achievement has independent intellectual property rights. It has published a monograph "River Basin Chemicals Management-Taking Dongjiang Basin as an Example", compiled a software "Dongjiang Basin Toxic Pollutant Data Information System", and obtained a software copyright registration certificate. The analytical methods and monitoring specifications for optimal control of pollutants in the system have received good feedback from the application of the Dongjiang Basin Environmental Monitoring Station, providing an effective management tool for risk control of chemicals in water quality in the basin.