The utility model discloses an instantaneous circuit protector against power failure of industrial computer hardware facility belongs to industrial computer hardware technical field. This instantaneous circuit protector against power failure of industrial computer hardware facility is including connecting the power down protection device between power and controlled motor, this power down protection device includes the controller, the synchronous voltage signal detection circuitry that is connected with the controller and connect the rectifying step -down circuit between both ends of the power supply, be connected controlled motor and switch between power one end and the synchronous voltage signal detection circuitry, the signal output part of controller connects a silicon controlled rectifier, the other end at the power is connected to a positive pole of silicon controlled rectifier, another positive pole is connected on the motor. The utility model discloses can accurate judgement for the electric situation of falling of the power of controlled motor power supply, avoid unexpected situation to take place, guarantee the automatic operation of low -risk of the controlled lathe of industry.