In many situations, the random coupling model (RCM) has been successfully demonstrated to predict the electromagnetic pulse effect within a complex enclosure. However, the model sets boundary conditions at infinity when calculating the coupling effect, which causes a problem named the short orbit effect. In this paper, a short orbit random coupling model (SORCM) is proposed by means of defining a short orbit correction coefficient of the radiation impedance in the two-port wave chaotic cavity. The results of the SORCM were compared with the experimental data, which shows that the SORCM is more effective compared with the RCM in predicting the statistical electromagnetic properties. The insights gained from the research can provide guidelines for the design of the electronic equipment.