Abstract: To improve the applicability and reliability of the hybrid switch realized by silicon carbide metal oxide semiconductor filed effect transistor (SiC-MOSFET) and silicon insulated gate bipolar transistor (Si-IGBT) in parallel connection (SiC/Si HyS), this paper proposes a SiC/Si hybrid switch drive circuit with variable drive voltage for the first time. It utilizes one PWM control signal and one driver chip to generate gate signals with different voltage levels to control SiC-MOSFET and Si-IGBT, respectively. Compared with the traditional SiC/Si HyS gate driver circuit with dual independent drive branch, the proposed drive circuit greatly reduces the complexity of SiC/Si HyS gate drive circuit design, while it reduces the possibility of Si-IGBT misdirection during SiC-MOSFET turning off, improving the reliability of hybrid switching. The working principle of the designed driving circuit is analyzed in detail, and the gate voltage adjustment is given. The mathematical model of the voltage ripple and the transient process of the coupling capacitor are established during system startups, and the accuracy is verified by both simulation and experiment. A 2 kW SiC/Si hybrid switch Buck converter is built based on the proposed drive circuit to verify the reliability of the system. The advantages of the proposed drive circuit are analyzed by comparison with the existing methods in terms of power losses of the SiC/Si power switches, power loss of the drive circuit, system cost and volume.