Abstract: In recent years,Beijing City has suffered frequent waterlogging disasters,particularly the old part of the city. In this paper,the flood protection and waterlogging prevention problems of the old city are analyzed and the corresponding solutions are put forward. Taking Beijing bus station for example, the risk of waterlogging and drainage before and after the construction of the project was simulated using the mathematical model,and different waterlogging control strategies were proposed based on the simulation results. It is found that rainwater control and utilization should be the key point of the flood protection and waterlogging drainage system when the outside drainage facilities are difficult to reconstruct;Gray infrastructures represented by rainwater pipeline play an important role and the source control based on green infrastructures has some good effect on the flood protection and waterlogging drainage system construction;It's suggested that the open space of the old city should be fully reconstructed and used in order to reduce the risk of waterlogging.