The deployment of artificial reefs can improve the ecological environment of local water areas in rivers,creating a favorable habitat for aquatic organisms such as fish.Based on the computational fluid dynamics (CFD) method,we study the hydrodynamic characteristics of a combination of triangular prism artificial reefs in the upper reaches of the Yangtze River.Using the geometric features of upwelling and back-eddy flows as parameters,we analyze effect of different inflow velocities (1.5 m/s,2.4 m/s,and 3.0 m/s) and layout spacings (0.5 m,1.5 m,and 2.5 m) on the flow field.The results show that with an increase in inflow velocity,the geometric characteristics of upwelling and back-eddy flow show minimal variation under the same artificial reef combination condition.As the layout spacing increases,the geometric characteristics such as the maximum height and volume of upwelling and back-eddy flow initially increase and then decrease under the same artificial reef combination condition,with 1.5 m being the optimal deployment spacing.Additionally,under the same flow velocity or layout spacing,an increase in the number of artificial reef combinations leads to a gradual increase in the maximum height and volume of upwelling and back-eddy flow,with a configuration of seven reefs as the optimal combination.