Although China's urbanization is developing rapidly and people's quality of life has been greatly improved, the water environment of people's life is getting worse and worse. Water pollution (WP) has become a major environmental problem endangering people's daily life. Water is an indispensable resource in people's daily life. People should cherish our limited water resources and strengthen the protection of water resources. Therefore, this paper deeply analyzes the current situation of WP in A city, and combines convolutional neural network (CNN) to simulate the morphological characteristics of pollutants in water. Through this study, it is found that the industrial pollution in City A has the greatest impact on the water environment. The industrial pollutants are directly discharged into the river basin, resulting in an increase in the content of COD, ammonia nitrogen and TP in the water body. In addition, there are problems in the prevention and control of WP in City A, such as weak government supervision, weak prevention and control willingness, and low participation of citizens in the prevention and control of WP. Therefore, this paper puts forward corresponding water resources protection suggestions, I hope it can provide reference for WP control in other cities.