Abstract: Plastic tunnel cultivation is an important production method for high-quality vegetables and flowers．Roller shutter device has been installed at top of plastic tunnel to control light and temperature, and most mechanisms of roller shutter device has been connected to plastic tunnel truss columns through triangular support frames．While ensuring mechanical performance indicators such as strength, reducing self-weight of triangular support frame not only lowered manufacturing costs but also effectively reduced load on plastic tunnel truss, thereby minimizing instability risk caused by high roller shutter device's center of gravity being too high．Three optimizable structural dimensions of support frame were taken as design variables．Initial sampling was performed using an optimal Latin hypercube design to construct a Kriging surrogate model, and a genetic algorithm was applied to perform multi-objective optimization design of triangular support frame, providing a reliable method for lightweight design of agricultural equipment such as plastic tunnels．Optimization results have shown that when three optimization parameters were set to 178, 153, and 242 mm, respectively, triangular support frame's weight was significantly reduced by 10.68%, the maximum von-Mises stress was decreased by 12.13%, and the maximum static deformation was lowered by 17.13%．