A power drive control device of an automatic door, including a gear box having a shell; and a motor drive, the motor drive having a front cover integrally made with the shell of the gear box together, and a back cover covered on the front cover to hold a motor shaft, a stator coil around the motor shaft, a light chopper, and a photoelectric pick-up device, the front cover having a receiving chamber, two recessed holes and one screw hole formed in the receiving chamber and adapted for securing the photoelectric pick-up device in place, the light chopper being mounted around a bearing around the motor shaft to act with the photoelectric pick-up device, enabling the photoelectric pick-up device to monitor the operation of the motor shaft.