The velocity of fluid in the aquaculture cage is closely related to the growth of fish.In order to study the characteristics of the flow field around the aquaculture plane net,the flow field of a rigid plane net was simulated numerically based on CFD theory and by using the porous media model.Firstly,the uncertainty analysis of the flow field was carried out,and then the numerical calculations were carried out in the plane net at different angles and velocity,and the results were compared with the experimental results.The results showed that the calculation results of the resistance and the lift of the plane net were consistent with the experimental results,which indicated that the method can accurately predict the force of the plane net and the flow field around the plane net.The velocity of the fluid near the net decreased quickly,then after a certain length the velocity of the fluid changed slowly.The blocking effect of the plane net on the flow gradually decreased when the velocity of the flow increased.The numerical simulation method in this paper could be used to simulate the flow field of the plane net,which had some academic research value and engineering practical value.