In order to explore the impact of land use structure change on the stormwater regulation and storage capacity, based on the land use data and soil data from 1980 to 2020, the runoff generation and distribution in the Chaohu Basin under different rainfall scales in different periods were analyzed by combining GIS and SCS models. The results show that from 1980 to 2020, the land use change in the basin mainly showed the increase of construction land and the decrease of cultivated land and forest land; the comprehensive index of land use in the basin continued to increase, with the high-intensity land use area increasing from 127 to 1, 624 km2. The area with poor permeability increased from 1,706.0 to 2,398.1 km2 from 1980 to 2020, which was mainly attributed to urban expansion. Compared with 1980, under different land use conditions, the runoff increased significantly with the same rainfall, which was mainly located in the Hefei area of the Chaohu Basin; however, with the increase of rainfall, the effect of runoff increase diminished gradually, the runoff in 2020 increased by 6.11%, 2.61% and 0.96% under different rainfall conditions(50, 100 and 250 mm). Therefore, it can be concluded that land use change is the primary factor of runoff change and rainfall comes the second. The research results are expected to provide some reference for the urban planning and urban stormwater risk management in the Chaohu Basin.