With the continuous improvement of China's urbanization level, people pay more and more attention to the harmonious development of ecological environment and health.Scientific analysis of hidden dangers of urban water source pollution and risk assessment and management can effectively reduce the impact of water source pollution on human health.For urban river water environment, in order to actively respond to the concept of sustainable development, we must do a good job in the ecological comprehensive treatment of urban river water environment, so as to fundamentally improve the quality of river water environment and ensure the safety of urban water use.The Yellow River is the main source of Baotou surface water source.Through the analysis of the environmental pollution characteristics of the West River in Baotou section of the Yellow River and the evaluation of water environment quality, the risk assessment of water environment is based on the construction of the risk assessment model based on the screening indicators of principal component analysis, determines the main pollutants and prediction results, and puts forward reasonable regional risk prevention measures, which has important reference value for the protection of water environment.