In order to accurately describe the wireless channel between the inspection UAV and GBS in the power transmission environment, we propose a three-dimensional channel model based on GBSM. The influence of tower poles and transmission lines in the transmission line environment is considered. The horizontal cylinders are used to describe the scatterer distribution of transmission equipment and the surrounding environment. In order to prevent the electromagnetic field generated by the transmission line from affecting the safety of UAV inspection operations, a safe flight area is set up in the model to ensure the safety of inspections. For the proposed channel model, channel statistical characteristics such as space-time correlation function，Doppler power spectral density，envelope level crossing rate and average fade duration are derived and analyzed. The influence of scatterer distribution and UAV motion status on channel statistical characteristics was studied. The simulation results show that the UAV′s speed, flight direction, and scatterer distribution have a significant impact on the channel. The theoretical results and simulation results are in good agreement, verifying the correctness and effectiveness of the proposed model, and can provide a theoretical reference for the design of wireless communication systems between inspection UAV and GBS in transmission line scenarios.