Abstract It is vital to precisely extract the actual vibration load spectrum of the electric drive assembly since it is a crucial piece of fundamental load data for vibration testing and vibration fatigue performance development. A simulation iteration-based vibration load spectrum extraction method for electric drive assemblies is proposed by actually measuring the six-component load spectrum. Establishing the whole vehicle system dynamics model with the electric drive assembly as the research object. Based on this, the vertical displacement and five-part force of the four-wheel centers serve as input signals, while the vertical force of the four-wheel centers serves as output signals. An iterative system was set up, and the frequency response function was obtained. The excitation signals of the simulated iterative system are obtained by the simulated iterative algorithm and verified, with all relative errors within 5.0%. The vibration load spectrum at the corresponding position of the electric drive assembly was extracted under the excitation signal. The results indicate that the simulation iteration-based method for extracting the vibration load spectrum of the electric drive assembly can accurately simulate the loads on the electric drive assembly during actual vehicle operation. This proves the effectiveness of the method for extracting the vibration load spectrum of the electric drive assembly.