Abstract: Located in southeastern Hubei province, Junshui River is one of the rainstorm centers in the province, and area with frequent flood disasters. In order to explore the impact of land use change on flood processes, the impacts of forest land, residential land, grassland and cultivated land on flood processes was calculated based on SWAT model and extreme land use scenarios. The results show that: (1)SWAT model has good applicability in flood process simulation of Junshui River Basin. The verification results of Tongcheng (II) hydrological station show that the qualified rate of flood peak is 83.33%, the certainty coefficient ENS is greater than 0.80 and the deterministic coefficient R² is greater than 0.9. (2)In different land use types, flood peak discharge and flood volume were increased by residential land and cultivated land, and the increase of residential land was more significant. Both forest land and grassland have the effect of reducing flood peak and flood volume. (3)The impact of land use type change on small and medium flood processes is more significant, while the impact on large flood processes is relatively weak.