Taking the central urban area of Shanghai City as an example, a numerical model of urban waterlogging inundation was constructed to simulate the waterlogging under the design rainstorm scenarios with return period of 50 a and 100 a. Combining the simulation results of road inundation and the calculation method of vehicle speed attenuation, the superposition of vehicle speed attenuation results and the simulation of urban road traffic status can obtain the road network operation status of the study area in peak and flat hump periods under different design rainstorm scenarios. The results show that urban waterlogging will significantly reduce the level of road traffic service, and the road operation state is closely related to the time period. The impact of waterlogging on road traffic is more significant during the peak period, which is mainly reflected by the significant increase in the number of road sections with low service levels. Under the design rainstorm scenarios with return period of 50 a and 100 a, the average road traffic speed in the peak period decreased by 19.3% and 37.4% respectively compared with the flat hump period.