In order to investigate the hydraulic characteristics of urban drainage pumping stations with curved inlet box culvert and explore the rectification measures to improve the adverse flow state inside the pumping station, the hydraulic flow state and rectification measures of urban drainage pumping stations were studied using the numerical simulation method, and the physical model was used to verify the rectification effect. It is found that the main stream of the forebay in the urban drainage pumping station with curved inlet box culvert is skewed and separated. The main stream of the forebay is concentrated in the middle and upper layers, and there is a large range of facade circulation in the middle and lower layers, and backflow in the bottom layer. The flow in the inlet pool is turbulent and vortices appear, resulting in the water not being able to enter the pump smoothly. The combined rectification measure of square column and combined beam was designed and optimized, and it is found that the combined rectification measure can improve the hydraulic flow pattern of the forebay and the inlet pool. The deviation and separation flow in the forebay are eliminated, the bottom backflow disappears, and the vortex in the inlet pool is effectively suppressed. The uniformity values of the inlet flow velocity distribution of the three water pumps were increased by 12.0%, 8.7%, and 8.3%. The weighted average angles of the inflow velocity were increased by 7.08°, 9.07°, and 11.40°.