Net enclosure aquaculture is one of the most important ways for farming fish and economic animals. Among them, nets, piles, ropes and iron chains can be used to delineate a certain water column in the shallow seas. More than 10 net enclosure facilities have been built across the country from the Shandong to Guangdong Province in China in recent years. However, only a few studies have been focused on the hydrodynamic performance of net enclosure aquaculture and emerging marine aquaculture facilities. The net enclosure facilities are still in the early stages. It is also lacking under the extreme ocean load resistance of aquaculture engineering structures. In addition, there is no such structural design theory or standard specifications for the net enclosure design and installation, particularly on the safety assessment. In this study, a net enclosure aquaculture facility was numerically investigated using the lumped mass model. A Newton’s second-law-based motion equation was then solved using Euler’s method. Finally, the MATLAB platform was used to visualize the calculations. The results showed that the maximum force of ropes was found in the second horizontal rope and the third horizontal rope under the still water level. Furthermore, the maximum forces of ropes and net twine were get the wave-current directions of 0°, 10°, 40°, 60°, and 80°, respectively, when the wave and current were 4 m, and 1.0 m/s, respectively. The force on the netting was tilted to the right (incident direction), as the incident angle was changed gradually. As such, the force on the right side of the rope was much greater than that left side. The maximum force on the right side of the horizontal rope was 27.04% higher than that on the left side at the wave-current incident direction of 10°. Moreover, the maximum forces on the right side were 42.44%, 86.01% and 92.15% higher than that on the left side in the wave-current incident direction of 40°, 60˚ and 80°, respectively. The maximum displacement of the net decreased greatly, as the incident angles increased and the maximum positions of the net moved to the left. The force of the net significantly increased with the waves. The load of the entire net was mainly from the top half of the net. The main force of the net twines was distributed in the six areas that were divided by the first three horizontal ropes and the two vertical ropes. The maximum force on the net twines occurs at the position on both sides above the second horizontal rope under the water surface. The force of net twines on the right side of the rope was greater than that on the left side, with the change of the incident direction. The maximum force decreased rapidly at the incident angle of 40°-80° under the combined wave-current conditions. The maximum force of joint points appeared at positions 1, 2, 3, and 4. The numerical simulation was then performed on the net of the seam-edge type net enclosure aquaculture facility in use. The force distribution and deformation were achieved in the seam-edge type net enclosure. The finding can provide the theoretical basis for the design, installation, and reinforcement of aquaculture facilities. In addition, it was necessary to focus on the inspection and reinforcement after the event of extremely bad weather.