To increase the voltage levels and reduce the harmonics feedback to the input source in high voltage high power application, this paper proposed one novel multilevel back to back AC-DC-AC converter. Firstly, the topology about this six level converter is introduced, which realize the neutral clamped points only by switches, and is attractive for its economy. The relationship between the multilevel voltage and the switches states are listed. Secondly, one reliable link voltage balance circuit is introduced that is simple to control. This balance measure ensures the converter is easy to realize and could be extended for general multilevel converters. Thirdly, the back to back configuration based on the six level rectifier/inverter is discussed. This control principle of this structure to obtain unity power factor and few harmonics is deduced. Lastly, the simulation results of this back to back converter validate the proposed method and demonstrate that this structure is hopeful for actual multilevel voltage application.