Bridge arm switching multi-level converter

The invention discloses a bridge arm switching multi-level converter which comprises six same bridge arms; each bridge arm comprises a plurality of H bridge submodules, a thyristor with an anti-parallel diode and an inductor which are serially connected; one ends of a first bridge arm, a second bridge arm and a third bridge arm are connected to the positive pole of a direct current power supply, and one ends of a fourth bridge arm, a fifth bridge arm and a sixth bridge arm are connected to the negative pole of the direct current power supply; and the other ends of the first and the fourth bridge arms are connected into an A phase output end, the other ends of the second and the fifth bridge arms are connected to be a B phase output end, the other ends of the third and the sixth bridge arms are connected into a C phase output end. The bridge arm switching multi-level converter has less loss, can be easily extended to a high-voltage grade and can maintain the stable operation of a system when a direct current bipolar short circuit fails to work.