The invention relates to an automatic chamfering machine. The automatic chamfering machine comprises a blank material clamping mechanism, a chamfering cutter and a chamfering cutter rotary driving mechanism. The blank material clamping mechanism comprises an installation frame, a blank material clamping claw and a clamping claw rotary assembly, wherein the blank material clamping claw is provided with a linkage shaft rotationally arranged on the installation frame; the clamping claw rotary assembly comprises a first motor and a linkage cam, the first motor is fixedly installed on the installation frame and provided with a first motor shaft in a driving mode, the first motor shaft is parallel to the linkage shaft, the linkage cam is arranged on the outer peripheral surface of the first motor shaft and peripherally rotates synchronously with the first motor shaft, and the outer peripheral surface of the linkage cam comprises a linkage part in abutting fit with the outer peripheral surface of the linkage shaft and an idle part far away from the outer peripheral surface of the linkage shaft. By means of the scheme, the automatic chamfering machine lowers the cost as a servo motor is not adopted.