A multi-frequency uniformization carrier wave slope random distribution pulse width modulation method, includes: (1) selecting a required random carrier wave sequence and a modulating wave, and after the two are compared, generating a switch device drive signal for pulse width modulation; (2) determining a multiple n of an equivalent carrier frequency f of the random carrier wave sequence, and selecting a main circuit topology; and (3) inputting the switch device drive signal generated in (1) into the main circuit topology of (2) to perform multi-frequency uniformization carrier wave slope random distribution pulse width modulation. The disclosure can improve a frequency domain distribution bandwidth of a harmonic wave without changing the mean and variance of a random carrier wave sequence, and realizes uniform distribution of carrier waves and multiple harmonic peaks near a doubled frequency of the carrier waves in a wider frequency domain.