The evaluation indexes of simulated results are shown in Table 2. It can be found that the GXM has achieved good flood simulation accuracy in the Tunxi and Qianhe River Basins, which makes it greatly practical in flood management and utilization. However, the simulation accuracy of the GXM in the Qianhe River Basin was lower than that in the Tunxi River Basin. By comparing the hydrographs of the above four flood events, it can be clearly found that the shape of the hydrographs in the Qianhe River Basin fluctuated more obviously and the difference in flood peak discharge was larger. The reason for the flood simulation results is mainly because the GXM is mainly suitable for humid and semi-humid areas, while the Qianhe River Basin is a semi-arid area. The formation process of rainfall runoff in semi-arid regions is more complicated than that in humid regions, with both full-storage runoff and excess infiltration runoff, which brings great difficulties to runoff simulation.