To study the rainstorm waterlogging disaster in Huinan, Pudong District, an urban waterlogging model coupled with the rainfall runoff sub-model, underground network sub-model and the overland flow sub-model has been set up by MIKE FLOOD. After the validation with the actual reports of the waterlogging in Huinan on Oct. 8th, 2013, the model is adopted to simulate the overland flood before and after Gongji Road Rain Pump works to study the impact of Gongji Road Rain Pump on the waterlogging disaster. The results are analyzed and the conclusions are obtained: when Gongji Road Rain Pump runs, the total flooded area will significantly decrease to .49 km2, about 21%, meanwhile, the drowned duration will be shortened in 6 hours, ahead 10 hours. Therefore, Gongji Road Rain Pump can alleviate the waterlogging, but some other measures are still needed to be taken to solve the waterlogging disaster.