The invention relates to a transformer-free inverter based on IEGT. The transformer-free inverted based on IEGT is characterized by comprising three phases, each phase is composed of several standard power units which are serially connected, and one ends of the serially connected standard power units are connected together and connected with a three-phase bridge type inverter. The other ends of the serially connected standard power units are connected with a reactor, the reactor is connected with a charge resistor, and after connected with a switch in parallel, the charge resistor accesses into the power grid through another switch. The transformer-free inverter based on IEGT has the advantages that a transformer on a conventional STATCOM (static synchronous compensator) grid connection side can be omitted, and the purposes for reducing cost, saving space and simplifying the structure are achieved.