The invention discloses an efficient motorized spindle structure which comprises a steel cylinder. A stator is fixed in the steel cylinder, a rotor is penetratingly arranged in the stator, a back cover is fixed onto the rear end of the steel cylinder, a cylinder assembly is fixed onto the rear end of the back cover and includes a cylinder drive shaft, a pull rod is arranged in the rotor, a pull claw is mounted at the front end of the pull rod, a cutter holder is clamped in the front end of the pull claw, and the cylinder assembly is used for driving the pull rod to slide forward to expand thepull claw; a pull rod air duct is formed in the center of the pull rod, a cutter removal air tap communicated with the pull rod air duct is arranged in the back cover, the front end of the pull rod air duct extends to the pull claw, the front opening of the pull rod air duct faces the rear end of the cutter holder, a seam is formed between the outer wall of the cutter holder and the inner wall ofthe rotor when the pull rod slides forward and the pull claw is opened, and airflow from the cutter removal air tap is blown out through the pull rod air duct and the seam to drive the cutter holder to be separated from the pull claw. By the arrangement, cutters can be replace rapidly so as to save operation time and improve working efficiency.