Aiming at the problem that the switching frequency of three-level neutral point clamped converter (NPC) increases, resulting in the increase of converter ripple current and electromagnetic interference noise, a variable switching frequency modulation strategy based on current ripple prediction is proposed to reduce the ripple current, harmonic noise and electromagnetic interference noise of three-level NPC converter. According to the requirements of current ripple, the switching period and sampling period are calculated to synthesize the latest switching period to form feedback, so as to realize frequency conversion modulation. The random period is distributed around the expected period, so that the harmonic noise and electromagnetic noise of the converter are more evenly distributed in a wide frequency band, so as to reduce the electromagnetic noise of the converter and improve the current ripple on the output inductance. Finally, the relevant simulation and experimental results verify that the common mode noise is reduced by about 20dB/μV, and the differential mode noise is reduced by about 10dB/μV. The amplitude of the inductance ripple current is also reduced.