The utility model provides a 110V DC power supply system of a converter station. The output end of the 1 # storage battery is connected to the first junction box; the output end of the 2 # storage battery is connected to the second junction box; the output end of the first junction box is connected to a fourth double-throw switch; the output end of the second junction box is connected to a fifth double-throw switch; the 1 # charger and the 1 # storage battery are connected to the direct-current feeder screen A through a first double-throw switch and a fourth double-throw switch; the 2 # charger and the 2 # storage battery are connected to the DC feeder screen B through the second double-throw switch and the fifth double-throw switch. The DC feeder screen A and the DC feeder screen B are connected with the DC feeder screen C through the change-over switch. The wiring mode can be changed quickly through the change of the position of the double-throw switch, the operation mode is very flexible, the operation is simple and convenient, the maintenance workload is small, the reliability is high, and the requirement of a converter station secondary system on a 110V direct-current power supply can be met.