Abstract: Abstract: The net enclosure aquaculture (NEA) is a new developing ecological aquaculture pattern in shallow water. The typical patterns include the pile-column type NEA, the shore-cascade type NEA and the floating rope NEA. The pile-column type NEA is mainly composed of piles and net panels. The net system is one of the most important factors which affect the security of the whole NEA system. Because of its especial structure, there are few related reports. Therefore, it is of great significance to carry out research on the hydraulic characteristics of unit net of pile-column type net enclosure in waves. Because unit net belongs to the typical flexible structure, the computing model can be established by the lumped mass point method. Based on Newton's second law, the equation of particle motion was established to illustrate the motion response of net panel in wave. Wave force can be calculated through the Morison equation. The equation of motion is a typical second order partial differential equation. There are a variety of methods to solve the equation, such as the Euler method and the Runge-Kutta method. In this paper, the program was computed in code, which could obtain a good convergence by using the Euler method. Firstly, the wave force on cables, and the strain produced by the cable deformation were calculated, with the assumption that the net panel was plane without deformation at the beginning. Secondly, the motion equations of each lumped point, which were typical second order partial differential equation, could be obtained according to the Newton equation. Then, the forward Euler's method was used to calculate the particle displacement and velocity at the next time step. Finally, the particle position and velocity were taken as new state parameters of net panel, and the above steps were repeated until the end of time. The results showed that wave height and wave direction had a significant effect on the maximum tension force in twines, the maximum displacement of nodes and the maximum load at fixing points. The maximum tension of netting twine mainly appeared on both sides of the top position of the net panels and it increased with the wave height increasing. Remarkable increase of the maximum tension in netting twines was found when the wave direction was between 30o and 70o. The maximum offset of net panels was observed mainly at the mid-upper position of the net and it showed a positive correlation with the wave height and wave direction. The maximum load at the fixing points on the pile-column appeared at the top point. The second maximum load point occurred at the bottom. Both of them were much larger than those at the middle fixing points. Therefore, in actual engineering, it is suggested that the fixing points at the top and bottom should be strengthened peculiarly, and the cables at both ends of the top and bottom net should be thickened. At the same time, the maximum offset and corresponding position are important indices for the layout of net and the installation of relevant equipment. So, the reasonable design of related spacing should be considered and the affiliated structures should not be installed within the maximum offset scope to prevent the cables and lines from breaking due to touching and friction. The results of this study are expected to provide theoretical basis and technical support for the design, production and offshore installation of the pile-column type NEA engineering.