Abstract: In order to explore the fishway chamber structure suitable for the migratory requirements of different water depths, this paper takes the fishway of Xiangshan hub in Ganjiang River as the research object, adjusts the traditional vertical joint fishway partition board into a hole plate overflow structure, and adopts the method of dimensional numerical simulation and physical model test to study the flow characteristics of the fishway chamber.The results show that at low water level operation, the vertical joint overflow way is a single vertical joint structure, which meets the requirements of low water depth fish in this river section.At high water level operation of physical model tests, the overall flow velocity of vertical joint was between 0.8 m/s to 1.2 m/s, and the overflow hole flow velocity is between 0.8 m/s to 0.9 m/s, which meets the requirements of fish passage at different water depths.The research results can provide a reference for the design of fishway.