The utility model provides a large-capacity energy storage converter formed by connecting multiple groups of inverter units in parallel. The large-capacity energy storage converter comprises multiple groups of independent DC (direct current) input inverter units and a network side isolation transformer, wherein the multiple groups of independent DC input inverter units are connected with one another on an AC (alternating current) side in parallel; and an input end of a parallel connecting circuit is connected to a 380 V power grid through the network side isolation transformer. According to the large-capacity energy storage converter, a large-capacity cell pack is optimized; a voltage equalizing and circulation current problem caused by connecting multiple groups of batteries in parallel can be completely solved; the risk of inconsistent characteristics caused by connecting multiple groups of battery modules in parallel is reduced; and the service life of the battery is guaranteed.