Based on the concept of field coupling, an electromechanical coupling model about antenna array of an active phased array is established. The array elements of the antenna array are arranged as a ring grid array, the radiation pattern of array factor and the radiation pattern of array are simulated. According to this ring grid array, the structural errors are added to the electromechanical coupling model, the effect data of structural deformation error, array machining error and accumulated installation error on the electrical performance of antenna a0r1ray are obtained. The effect of structural errors on the electrical performance of antenna array such as antenna gain, grating lobe level, beam pointing and beam width is researched, the effect on the electrical performance by the displacement response of antenna array to firing vibration can meet the requirements of the system, as while as the effect on the electrical performance of antenna array by array machining error and accumulated installation error is less.