Based on practicability analysis of SWMM model parameters in the calibration process, four parameters of subcatchment slope, subcatchment width, Manning coefficient and depression depth on pervious area and three infiltration parameters were selected. Two popular infiltration models of Horton and Green—Ampt were examined respectively. Global sensitivity analysis method of Morris was used. Flow metrics of total rainfall depth and peak discharge were simulated for single rainfall events with different rainfall types and return periods while runoff coefficient was examined for the long-term rainfall data. Main results were: sensitivity analysis results for T1 and T2 rainfall events indicated great differences and T2 rainfall event with small return period was not suitable for parameters calibration; for Horton model, peak discharge of large T1 rainfall can be used for calibrating subcatchment width and slope while total runoff of large T2 can be used for calibrating infiltration parameters; for Green—Ampt model, peak discharge of small T1 rainfall can be used to calibrate subcatchement width and that of large T2 rainfall can be used to calibrate minimum infiltration rate and water deficiency; for the runoff coefficient, sensitivity analysis results of the two methods are similar.