Abstract: Based on the MIKE flood ,the MIKE11, MIKE URBAN and MIKE21 are coupled to analyze the flood problem of Shiyan subdistrict in Shenzhen, including the evaluation of riverine flood control capacity, pipeline drainage capacity, flood risk analysis and the determination of rainfall threshold for waterlogging. The simulation results show that the flood control capacity of Shuitian Tributaries is less than 2 year return period, and the flood control capacity of Shangpai River is less than 5 year return period. The 34.24% of Shiyan subdistrict's pipelines have a drainage capacity of less than once in a year, 17.59% have a return period of 1～5 years, and 48.17% have a drainage capacity of more than once in 5 years. When the pipe network standard is raised to more than once in three years, the urban drainage capacity can be greatly improved. The main causes of waterlogging at waterlogging prone points reported in history are as follows: local low-lying areas with large catchment area; insufficient drainage capacity of the pipeline itself including mainly the problems such as connecting large pipes with small pipes, adverse slope, too small pipe diameter, etc.; jacking by downstream river water level. According to the analysis, the rainfall threshold of flood is evaluated in Shiyan subdistrict. When the rainfall reaches 20 mm in 3 hours, the exit of Longda Expressway on Shilong Avenue is a low risk point, when the rainfall reaches 40 mm in 3 hours, it becomes a high risk point; When the rainfall reaches 60 mm in 3 hours, the flood point at the bridge and culvert of Longda Expressway on Zhulongtian Road is a high risk point; When the rainfall reaches 70 mm in 3 hours, Qingnian Road is a high risk point; When the rainfall reaches 80 mm in 3 hours, the intersection of Guangming Road and Aiqun Road is a high risk point.