Abstract: In view of problems that normal cascaded H-bridge converter needs multiple DC power supplies for topology and is difficult for realization of four quadrant running, or needs high cost and complicated control algorithm, a topological structure of three-phase interconnected cascaded converter is put forward with modulating solution. By every two phases interconnection of 3 three-phase two-level converting circuits, the converter has simple structure and high utilization efficiency of DC voltage; employing sample-time-staggered pulse-width modulation technology, and has lower switching loss and output waveform distortion. Matlab/Simulink simulation result shows that the three-phase interconnected cascaded converter based on sample-time-staggered pulse-width modulation has better sine wave and lower harmonic content for output waveform.