As a frequently inundated region in Nanjing, Guangzhou Road and its surrounding area were selected as the study site in which a one-dimensional storm flood model was built based on SWMM. The inundation induced by the storm event occurred in July 18^th, 2011 was simulated using the measured rainstorm data. The function relationship between the total cumulative inundation volume and the maximum inundation depth was fitted, and the starting and lasting time of the inundation and the maximum inundation depth were calculated, which were compared to the inundation induced by the design storm with 100-year return period in Nanjing. The results reveal that the fast calculation method for the maximum inundation depth proposed in this paper can dynamically calculate the inundation induced by the storm in July 18^th with high simulation accuracy, which can timely and effectively support flood control and drainage emergency decision-making. Compared with the storm in July 18^th, the maximum inundation depth and the lasting time of inundation remarkably increase under the condition of the design storm with 100-year return period.