The present disclosure relates to an inverter system capable of detecting an output ground fault and an output ground fault detection method using same and, particularly, to an inverter for detecting an output ground fault by detecting the current of a leg-shunt resistor, and an inverter output ground detection fault method using same. The present disclosure compares absolute peak values of 3-phase current AD raw values detected from a shunt resistor, and thus may reliably detect the output ground fault of an inverter.