The frame of spherical stabilized platform is the main part and the key component. The initial main frame of a spherical stabilized platform is designed. In order to make the main frame of a spherical stable platform lighter and more rigid, the improved design is carried out. The SolidWorks software is used to conduct 3d model for the initial design and the improved design, and to compare the quality of the two designs. The finite element model of the two designs is carried out by using ANSYS software, and then the modal analysis is carried out to obtain the first natural frequency of the main frame. The comparison results show that the improved design is lighter than the initial design, the first-order natural frequency is improved, the corresponding stiffness is greatly improved, and the resonance does not occur in the frequency range of 80Hz [?] 160Hz, which meets the design requirements. Finally, the improved four-jaw design is adopted to provide a reference for similar platform design.