To enhance the efficiency of reconnaissance and surveillance in space optical systems， reduce the mass and power consumption of onboard payloads， and optimize onboard resource allocation， a lightweight design for a two-dimensional turntable is developed to improve its payload ratio. This paper presents an optimization method for selecting FEA parameter response surfaces tailored to two-dimensional turntables， enhancing mechanical simulation accuracy through the integration of FEA simulations and mechanical tests. First， an FE mechanical mesh model of the structure is established. Significant simulation parameters are identified as matching targets through significance analysis. The quadratic response surface coefficient matrix is then derived using the least square method， and the response surface's effectiveness is evaluated. Finally， the optimized model parameters are determined using an optimization algorithm. Utilizing the matched FE model， mechanical analysis of the two-dimensional turntable is conducted， and results for three structural responses below 100 Hz-modal frequency， low-frequency sinusoidal vibration acceleration response at characteristic nodes， and random vibration stress response at characteristic nodes-are obtained. Compared to dynamic tests， the maximum error in results decreased from 8% to 3%， 17% to 4.9%， and 8.5% to 2.2%， respectively. This approach significantly improves mechanical simulation accuracy， fulfilling engineering application requirements. It has been successfully applied to the development of a two-dimensional turntable， increasing its payload ratio from 0.6 in the previous generation to 1.6.