An emergency startup device of an electric vehicle has a high-voltage power battery, a motor driver, a high-voltage control box, a vehicle controller, a low-voltage DC battery, and an emergency starter. The vehicle controller turns on or off the high-voltage control box. When the low-voltage DC battery does not have enough electricity to provide electricity to the vehicle controller, the vehicle controller may not turn on the high-voltage control box, the high-voltage power battery may not provide electricity to the motor driver, and the electric vehicle may not be driven. When the emergency starter is operated, the high-voltage power battery charges the low-voltage DC battery through the emergency starter. Then, the low-voltage DC battery provides enough electricity to the vehicle controller, and the electric vehicle is normally driven.