A mechanical displacement limit is designed to meet the usage requirements of the electro-optical turntables with an azimuth rotational angle of 0~±180°. Based on the structure, a finite element simulation model is established, and the effectiveness of the mechanical limit finite element simulation model is verified through physical experiments. Combining with the simulation results and experiments, the turntable control program is optimized,and the structure of the displacement limit is improved and enhanced. And the application scenarios are expanded.The displacement limit has the advantages of simple structure and low cost.