Affected by the limitation of offshore aquaculture space and environmental pollution problems, the marine aquaculture industry has gradually developed into the deep sea. However, the climate in the deep sea is more severe and complex. In order to ensure the structural safety of aquaculture equipment, it is necessary to conduct research on its hydrodynamic characteristics. As an important aquaculture equipment, the fishing net is taken as the research object. The porous medium theory was used to model the structure of the net,  the open source CFD software OpenFOAM was used to conduct numerical simulation research, and the interaction of the net with regular waves and focused waves was explored. The results show that in the case of regular waves as input, with the increase of solidity ratio of the fishing net and the characteristic velocity, the resistance of the net increases gradually, and with the increase of the characteristic length, the transmission coefficient of the wave behind the net location increases gradually; in the case of focused waves as input, the frequency domain distribution did not change significantly, and with the increase of mesh size, the mesh resistance gradually increased. Finally, based on the results of numerical results, the Reynolds number and KC number are used as output parameters to establish a prediction model for the mesh resistance of porous media under extreme waves.