Terminal equipment represented by inspection robots is widely used in substations. In the future, 5th-Generation (5G) mobile terminals will be more and more used in substations with the fast development of 5G technology. The performance of the communication system is closely related to the wireless channel. Therefore, it is very important to study the 5G communication channel characteristics of the mobile terminal in the substation. Aiming at the characteristics of the communication channel of 5G mobile terminals in the Three-Dimension (3D) scattering environment of substations, based on the multiple input multiple output technology, the article proposes to use geometric analysis to establish a 3D channel model, and derive the time autocorrelation function and spatial cross correlation function of the channel. Based on the 5G frequency band, the auto-correlation and cross-correlation characteristics of the wireless channel are simulated and analyzed. The influence of the Rice factor of different sizes on the wireless channel characteristics is also studied. The above simulation results show the availability of 5G terminals in substations, and broaden the research on mobile terminals using 5G communication technology in substation scenarios.