The invention provides a constant-voltage sorting charging method of a hybrid MMC and a starting method and device. The constant-voltage sorting charging method comprises the steps of sorting full-bridge sub-modules and half-bridge sub-modules; cutting off a plurality of sub-modules with relatively high voltage for active constant-voltage charging until the voltage of the sub-modules is close to a rated value; unlocking a converter; and when the full-bridge sub-modules receive a lock instruction for charging, conducting any full-controlled device and turning off other three full-controlled devices. The charging starting process of the hybrid MMC employing the sub-modules can be completed without judging the current direction, so that the problem of voltage fluctuation of sub-modules at the end of the charging stage due to the fact that a half-bridge topology and a full-bridge topology are not consistent is effectively solved.