The invention discloses a stepping drainage structure used for a double-layer open passage car. The structure comprises a drainage plate and a drainage tank. A water baffle is fixed to one side of the drainage plate, and the included angle between the water baffle and the drainage plate ranges from 90 degrees and 135 degrees. Through holes are evenly formed in the surface of the drainage plate, a carriage is fixed to the end face of the drainage tank, and the included angle between the surface of the carriage and the bottom face of the drainage tank ranges from 0 degree to 5 degrees; a water leaking hole is formed in the bottom face of the drainage tank, a drainage connector is fixed to the bottom face of the drainage tank, and the fixing position of the drainage connector corresponds to the water leaking hole. The drainage structure is arranged on the stepping position of the double-layer open passage car, is composed of the drainage plate and the drainage tank, and is convenient to install and convenient to detach and clean. The problems that in passage car manufacturing industry, water accumulated due to stepping of the double-layer open passage car is not easy to drain, upper layer accumulated water cannot be drained in time, and floors and interior parts are soaked for a long time are solved.