Abstract: With the development of radar towards high integration, high power and multi-function, the structure of antenna faces many challenges, such as high integration design, lightweight design, power resistance design and electromagnetic shielding design. Among them, with the increasing power and requirements of multiple functions, the design of electromagnetic shielding structure is becoming more and more important. In this paper, in view of the high power characteristics of a special radar system, the strict electromagnetic shielding effectiveness requirements were put forward. According to the structural characteristics of array antenna, the electromagnetic shielding design of antenna was researched detailly. From the aspects of shielding effectiveness distribution, shielding design of telecommunication basis, shielding material selection, electromagnetic shielding design of shot and hole structure. The improved structure of correlation shielding effectiveness was verified to be effective by in-plane and in-field tests.