Abstract: To satisfy the requirements of short development period and low cost of the modern radar, the FEM calculation of the antenna is necessary at the stage of structure design. In this paper the finite element model of the antenna framework structure is established, the static analysis and the mode analysis are conducted in the actual environment conditions through ANSYS. The stress distribution graphs and deforming graphs under different environment conditions are obtained by static analysis. The first four-order inherent frequencies and vibration modes are obtained by mode analysis. The stiffness and strength performance of the framework are verified. The results show that the strength and stiffness of the structure can meet the design requirement.