Abstract: A method for suppressing a direct current-link (DC-Link) capacitor current ripple (CCR) of a coupled three-level inverter (TLI), including: dividing space vector diagram regions of coupled TLI based on value range of virtual voltage vector duty cycle distribution factor; determining, based on amplitude, phase angle, and three-phase output current of reference voltage vector, sector and region in which reference voltage vector is located; then selecting nearest one virtual voltage vector and two basic voltage vectors, to calculate duty cycles thereof, respectively; designing a controller, updating duty cycle distribution factor of small vector based on sector and region in which reference voltage vector is located, set value of voltage difference across DC-Link capacitors, and actual value of voltage difference across DC-Link capacitors; and designing switching sequence based on updated small vector duty cycle and sector and region in which reference voltage vector is located.