The utility model provides a four -quadrant electric current source transverter based on auto transformer, include: auto transformer, alternating?current?power?supply, inductance, three phase bridge and direct current harmonic injector circuit, wherein, auto transformer's input links to each other through the output of inductance with alternating?current?power?supply, and its output links to each other with three phase bridge's input, and three phase bridge's output links to each other with direct current harmonic injector circuit. The utility model discloses main topology adopts based on the auto transformer, connects the direct current injector circuit through two sets of three -phase bridgings, through control dc circuit's injection current, to auto transformer's output current modulate, and then reaches the purpose that restraines the harmonic.