The invention discloses an MMC topological structure. The MMC topological structure is characterized by comprising three-phase bridge arms, wherein the three bridge arms comprise N+1 sub modules, N+1electric reactors and N sub module capacitors; each sub module is formed by two thyristors in an anti-parallel mode; one end of each sub module is connected with one electric rector in series, and theother end of each sub module is connected to the bridge arm where the sub module is located; the sub module capacitors are connected between two adjacent electric reactors in series. The MMC topological structure disclosed by the invention can effectively solve the problems existing in effective utilization rate and high equipment operation cost of equipment in the prior art. The embodiments of the invention further disclose a sub module input control method of the MMC topological structure and a sub module removal control method of the MMC topological structure, and flexible and reliable structure control and easy expansion can be realized.