In recent years, frequent urban flooding has brought serious challenges to urban drainage & flood prevention. Storage tank is an important part of urban flood control system. The selection of storage tank pre location-selection is related to its benefit and cost, and also affects the subsequent optimal solution. Based on the SWMM model, five indicators, including flood depth, flood area, flood duration, storage tank construction cost and node importance, were selected according to the flood prevention and control criteria. With the aid of the Analytic Hierarchy Process (AHP), the quantitative evaluation framework was established. The approach of pre location-selection scheme of storm water storage system based on pre location-selection index was discussed and verified by a case study. The results showed that, the storage location selection had significant influences on the proportion of flooding reduction. The proposed method was feasible and practical, and better pre location scheme could be obtained using this method. This study can provide technical supports for the site selection of storage tank in urban flood control.