The invention discloses a half-bridge and full-bridge mixed type MMC topology with a voltage enhancement characteristic. The half-bridge and full-bridge mixed type MMC topology comprises a coupling transformer, a full-wave bridge rectifier, an upper bridge arm half-bridge area Zp1, an upper bridge arm full-bridge area Zp2, a lower bridge arm half-bridge area Zn1, a lower bridge arm full-bridge area Zn2 and a precharging switch K3. One side of the coupling transformer is connected with a three-phase alternating current inlet wire, and the other side of the coupling transformer is provided with a first voltage source and a second voltage source. The upper bridge arm half-bridge area Zp1 and the lower bridge arm half-bridge area Zn1 are each formed by connecting N half-bridge submodules in series, and the upper bridge arm full-bridge area Zp2 and the lower bridge arm full-bridge area Zn2 are each formed by connecting K full-bridge submodules in series, wherein N and K are positive integers, and K is larger than or equal to N. The half-bridge submodules and the full-bridge submodules are mixed to modulate the alternating-current and direct-current voltage, the direct-current voltage can be increased, the direct current can be reduced, the fault direct current is turned off, and the purposes of voltage enhancement characteristic and fault ride-through are achieved.