UPS system of fault-tolerant inverter

The embodiment of the utility model discloses a UPS system of a fault-tolerant inverter. The UPS system includes: a UPS; a storage battery, an inverter and a rectifier, wherein the inverter comprisesa capacitor circuit, a three-phase six-switch circuit and a bidirectional thyristor branch which are connected in parallel to a direct-current side bus; wherein the input end of the three-phase six-switch circuit is connected to the storage battery pack; the three-phase six-switch circuit is provided with a three-phase power supply output end; the bidirectional thyristor branch comprises three paths of bidirectional trigger thyristor circuits; the input ends of the three bidirectional trigger thyristor lines are connected to the middle point of a capacitor circuit of the capacitor circuit, andthe output end of each bidirectional trigger thyristor line switch tube line of the three bidirectional trigger thyristor lines is connected with one phase power supply output end. According to the UPS system of the fault-tol