Due to the complexity of the high voltage power grid, the complexity and difficulty of the modeling are increased greatly when the harmonic analysis is carried out for a certain area of HV system. Therefore, a simplified model based on the integrated electrical analysis software ETAP is proposed. Firstly, the single line diagram of the power system is built according to the geographical position in the ETAP editing interface. Secondly, the measured data is input into the model and simulated. Finally, harmonic analysis is used to compare the simulation and measured values, allowing both errors to be within a certain range, and the correctness and effectiveness of the models such as power plants and substations are verified. Results shows that the model simplification scheme is feasible.