The layout of fishway entrance directly affects the effect of fish inducing and the efficiency of fish passage. Taking the case of Linhuaigang hydro-junction, this paper presents a fine simulation of the downstream river flow field under typical conditions by constucting a two-dimensional numerical model of the flow field in wide and shallow rivers, and compares and studies three different layout schemes combining with the results of acoustic investigation of fish distribution in the reach. The results indicate that flow velocities on the left and right banks downstream of the sluice meet the suitability conditions for fish, and are close to the fish aggregation area, which meet the requirement for the arrangement of the fishway entrance. To determine the layout scheme, the economic benefits, construction difficulties and engineering safety should be considered, and the sluice gate operation scheme should be adjusted accordingly.