Aiming at the problems of the existing multilevel converters, such as the large number of devices, high loss, and low power density, a novel hybrid multilevel converter (HMC) topology is proposed in this paper. The HMC consists of a three-level neutral-point clamped (NPC) cell configured with Si GTO and a cascaded H-bridge (CHB) cell configured with a mixture of Si IGBT and SiC MOSFET. For this topology, a specific hybrid high-low frequency modulation is proposed to give full play to the advantages of low switching loss of SiC devices and low on-state loss of Si-based devices. In addition, in order to solve the problem of unbalanced capacitor voltage of the hybrid topology sub-modules, an alternate voltage balancing control (AVBC) strategy is proposed. Finally, the feasibility of the HMC topology and modulation is verified by simulation.