The intelligent inspection of substations is widely conducted using UAVs, which results in higher requirements being placed on the safety inspection of UAVs, due to the tightness of the space around each device in the substation and the complexity of the electric field. The electrical and structural parameters of instrument transformers, circuit breakers, and transformers in a 220 kV substation are targeted, and an electric field simulation model is established based on the finite element method. The electric field distribution characteristics around the equipment inside the substation are obtained through mesh splitting and boundary condition setting. A UAV simulation model is established based on the structural parameters of the UAV. The electric field distribution along different paths around the instrument transformers, circuit breakers, and transformers is analyzed by combining the electric field calculation method with the UAV simulation model. An important theoretical basis is provided by the above study for obtaining the electric field distribution around key equipment in substations and improving the safety inspection of UAVs.