Abstract: The SWMM model has been widely used in urban rainfall-runoff simulation and design of sponge cities. A quantitative analysis on the parameters of this model is crucial to parameter identification and uncertainty reduction. In this study, a variance-based Sobol method and different accuracy assessment standards are used to quantitatively analyze the sensitivity of the SWMM model parameters in a case study of the Huangtaiqiao catchment under floods of different levels. Results show that (1) the parameters are different in sensitivity when accuracy assessment standard or flood level is varied, indicating a great uncertainty in model parameters. (2) The Nash coefficient depends much on Dstore-Imperv, MinRate, Roughness (rivers), and Roughness (conduits). (3) Interaction between the parameters is frequent in small flood cases, while it diminishes with a trend toward concentration as flood level is raised. (4) The Sobol method, suitable for the sensitivity analysis of urban hydrological models, can provide the sensitivity of each parameter and the interaction between different parameters.