The invention discloses an automatic plank holing machine. The automatic plank holing machine comprises a base. Supporting legs are arranged at the bottom of the base. A guide block is arranged at one end of the upper surface of the base. An inclined hole is formed in the upper surface of the base and is located at the left end of the guide block. Auxiliary legs are arranged on the upper surface of the base, and the tops of the auxiliary legs are fixedly connected with one end of the bottom of a hydraulic cylinder. A hydraulic telescopic rod is arranged at the bottom of the hydraulic cylinder, and one end of the hydraulic telescopic rod is fixedly connected with the top of a motor. One end of a rotating shaft of the motor is fixedly connected with a circle cutter. According to the automatic plank holing machine, due to arrangement of the guide block, planks can be placed on the holing machine by people more conveniently and rapidly, the hydraulic telescopic rod can descend to drive the motor to descend by starting the hydraulic cylinder, and the planks can be holed through the circle cutter on the rotating shaft of the motor; and after the holing machine completes holing of the planks, due to the fact that one side of the motor is connected with a cant hook, a hook block on the cant hook can raise the planks, the center of gravity of each plank deviates towards the inclined hole, and the planks on the base can slide out of the inclined hole.