To provide a highly reliable power shutdown control system certainly preventing an over-current from continuously flowing.

A power shutdown control controller 7 drives a current sensor 2 monitoring the current value of a current led to flow into the electric cable 5 of a power circuit when receiving a collision prediction signal predicting generation of collision of the front of one's own vehicle or the rear thereof with an obstacle from a collision reducing system 8 as a collision predicting means. After that, the controller transmits a control signal for disconnecting the electric cable 5 to a circuit switch 4 so that the electric cable 5 is disconnected by the circuit switch 4, when receiving from the current sensor 2 an over-current sensing signal representing that it is detected that the current of the current value exceeding a predetermined current threshold is led to flow into the electric cable 5. Thereby, electric supply operation is shut off. The collision reducing system 8 predicts generation of collision of one's own vehicle based on at least a distance between the front or rear of the one's own vehicle and the obstacle and a relative speed difference therebetween.