The utility model provides a discharging dolly electrical fault rapid determining apparatus. Three-phase power lines connected among two motors, two motor brakes and protectors are respectively additionally provided with breakers, power is supplied to the two motors and the two motor brakes separately, a discharging dolly is provided with an intermediate power box, and the breakers are arranged in the intermediate power box. In case of a blackout, all switches on the discharging dolly can be disconnected so that which motor fails can be detected directly, and at the same time, whether a power supply has an open phase and other problems can be safely detected under the condition that the discharging dolly does not run. If one motor is burnt and production is urgently needed, the breaker of the burnt motor can be disconnected, the motor brakes and the breaker of the other motor are closed, production is ensured firstly and then first-aid repair processing is carried out, such that the fault processing time is shortened, production is rapidly recovered, coke oven and sintering production are ensured, and blast furnace material blowing-out phenomenon can also be avoided.