A door operator with high-speed operation and fire escape functions comprises a motor, a high-speed centrifugal brake module, a centrifugal reduction module, a central shaft locking module and a first and second clutch module. In the stationary state, the high-speed centrifugal brake module, centrifugal reduction module and central shaft locking module are connected to each other, and the drive shaft of the motor is locked by the central shaft locking module. In the normal operation, the first clutch module disengages the high-speed centrifugal brake module from the centrifugal reduction module, and the drive shaft is rotatable at high speed. In the event of fire escape, the second clutch module disengages centrifugal reduction module from central shaft locking module, and the drive shaft rotates at a lower speed. The device will provide high-speed rotation under normal operation, and automatically close the door panel at a gradually lowered speed in the event of fire escape.