Abstract: The insulation systems of electric vehicles driven by pulse width modulation (PWM) technology are subjected to severe high-frequency PWM voltages. The fundamental frequency and carrier frequency are critical parameters of the PWM voltage. This paper establishes a high-frequency endurance testing platform to investigate the effects of varying fundamental and carrier frequencies on the partial discharge distribution characteristics and insulation endurance lifetime of the magnet wire in electric vehicle drive motors. The test results and analysis indicate that, under PWM voltage, partial discharges are primarily concentrated at the points of fundamental polarity reversal, exhibiting an asymmetric distribution. A frequency-lifetime inverse power model was used to fit the endurance lifetime so as to obtain the predictive models of different fundamental frequencies and carrier frequencies with endurance lifetime. The results show that the endurance lifetime of the samples decreases exponentially with increasing fundamental and carrier frequencies. When the fundamental frequency is constant, the voltage endurance lifetime curves at different carrier frequencies exhibit a parallel trend after inverse power transformation. Thus, the coupling interaction between the fundamental frequency and carrier frequency can be considered as a vertical shifting constant factor in the frequency-lifetime inverse power model. This research is expected to provide both experimental and theoretical supports for testing the endurance lifetime of electric vehicle motor insulation.