From the perspective of structural design, the design points of electromagnetic shielding for electronic cases are described. And the design method of electromagnetic shielding in structural design is presented. The Ansoft HFSS software is applied to simulate the case of an electronic equipment. And the distribution of the inner field of the case and shielding effectiveness of electronic equipment case are calculated. Through optimizing the layout of the device and the reasonable design of the case plate board, the purpose of improving the electromagnetic shielding effectiveness is achieved.