Abstract: To ensure that the fish can sucessfully pass though the fishway of Gongzui Hydropower Station in Dadu River, in this paper, the distribution characteristics of fish cluster in the downstream of Gongzui Hydropower Station are analyzed based on the hydroacoustic survey results and the flow conditions of the studied river section, the main upstream fish passage is extracted according to the suitability characteristics of the main fish passage objects regarding the hydraulic factors, and the fish passage inlet layout plan of Gongzui Hydropower Station is finally demonstrated. The results indicate that the vertical distribution range of fish is 1.15-11.62 m, mainly distributed in the middle and lower water area; fish clusters are mainly concentrated in the middle and upper reaches of the river section; fish upstream channels are located in the water close to both banks, and the range of velocities is 0.1-1.2 m/s; in the area from 29.290°N to 29.292°N, there is a concentrated distribution area of fish across the entire river width, indicating that the flow field conditions in this area can better meet the upstream demand of the fish in the study river section. This study demonstrates the layout of fishway entrance in two aspects: fish clusters and upstream channel distribution, and a more reasonable layout scheme of fishway entrance is proposed, which can provide a methodological reference for the layout of fishway entrance of other hydropower stations.