A quick-release apparatus which is adapted for a knife board of a saw grinding machine comprises a fixture plate forming with a first projection; wherein the knife board includes a coupled portion having a slot to hook the first projection; a fastening member mounted onto and not pivot with respect to the first projection of the fixture plate and including an exterior side having at least one concaved portion; and a control member pivotably connected to the fastening member and including an abutted side and at least one protruding portion formed on the abutted side, with the abutted side and the at least one protruding portion both corresponding to the at least one concaved portion, with the abutted side facing the fastening member, and with the at least one protruding portion selectively pressing the exterior side of the fastening member to tightingly attach to the knife plate.