Navigation is one of the functions of Xiangjiaba Hydropower Station.To give full play to the navigation benefits of the power station and clarify the suitable navigation flow conditions for the power station，the maximum navigation flow of the power station was preliminarily determined to be not more than 8 500 m3/s and the maximum flood discharge is not more than 2 200 m3/s dual-control standard through the full-scale ship trial navigation tests in the early stage.However，in recent years，it has been found that the navigation flow conditions of Xiangjiaba Hydropower Station are not only affected by the discharge flow，but also affected by the flood jacking effect of the downstream Minjiang and Hengjiang rivers.By establishing a one-dimensional unsteady flow model from Xiangjiaba to Luzhou，this paper simulates the daily and hourly variation of water level at Xiangjiaba Hydropower Station after encountering different typical annual frequency floods of Minjiang River and Hengjiang River with 5-100 years return periods during the flood season，when the flow rate of Xiangjiaba Hydropower Station is constant at various levels from 4 000 m3/s to 8 000 m3/s，respectively.It is calculated that when encountering the 50-year flood of Minjiang River and the 100-year flood of Hengjiang River，the hourly variation amplitude of the maximum water level at Xiangjiaba Hydrological Station is 0.55 m/h and 1.19 m/h respectively，and the daily variation amplitude of the maximum water level is 7.59 m/d and 6.87 m/d respectively.In addition，only when encountering the flood jacking of Minjiang River and Hengjiang River with a return period of 5-10 years，the water level of Xiangjiaba Hydrological Station meets the dual control requirements of no more than 1 m/h and no more than 3 m/d，and the water level variation under other conditions exceeds the standard.The research results can provide a reference for the navigation dispatching of Xiangjiaba Hydropower Station in the future.