In order to ensure the safety of urban drainage and alleviate the urban waterlogging, aiming at the dynamic influence of river drainage level on the drainage of pipelines, the draining area of Maling River in Suqian City is chosen as the study area. Based on storm water management model(SWMM), the changes of relative drainage capacity of free-flow pipe, semi-submerged outflow and completely submerged outflow were simulated in the case of design storm return period being 2,3,5 years. And on this basis the Maling River sub-controlled water level was explored. The results showed that the water flow in the pipeline is mainly affected by the high water level. When the pipeline is fully submerged, the drainage capacity decreases with the rise of the water level. The decreasing degree is related to the height difference of the terminal pipe and the water flow by the dynamic backwater effect. This conclusion can provide a scientific reference for pipe network reconstruction and river regulation for waterlogging.