With the acceleration of urbanization，industrialization and rapid growth of urban population，urban water problems such as flood control，deterioration of water ecological environment and water pollution are becoming more and more serious，and urban hydrology is becoming more and more important.This paper systematically analyzes the hydrological work of Jiujiang city，and puts forward some suggestions to improve the hydrological monitoring and early warning system of water logging in the city，establish the hydrological monitoring system of rivers and lakes in the city，and strengthen the scientific research of urban hydrology.