Abstract: The crest factor is an important index to evaluate the performance of the high-power aviation power supply vehicle. In this paper, a new crest factor analysis method combining parabolic interpolation method and least square method is proposed. Firstly, parabolic interpolation method is used to segment and expand the collected output voltage data of power supply vehicle. Secondly, the data fitting of least square method is realized under the simulation software, and the crest factor is analyzed. Finally, the crest factor of the output voltage of the prototype power supply vehicle is measured by the test system of the aircraft power supply vehicle. The experimental results show that the crest factor of the simulation experiment is 1.4285, and the measured crest factor is 1.42, and the simulation analysis results are basically consistent with the measured results. This research method plays a certain technical support role for the principle design and prototype manufacturing of high-power aviation power supply vehicle.