In recent years, the gradual increase of groundwater depth may cause large proportion of leakage, which may influence flood routing obviously. For that reason, flood routing model considering groundwater leakage was established taking Xiaoqinghe flood diversion area and 'its west zone as study object. The model was applied to simulate the flood design-standard of Xiaoqinghe flood diversion area. Then the influence of groundwater leakage on flood level of the Xiaoqinghe flood diversion area in Hebei Province, and flood level of Dongcicun station, which is the exit of the flood diversion area, was analyzed. The study result indicated that groundwater leakage had great effect on flood routing in the Xiaoqinghe flood diversion area. Therefore, groundwater leakage must be considered sufficiently in flood control and manage, and construction planning.