The invention discloses an A-type central drill of integral hard alloy, which comprises a drill handle, a drill bit, an oblique cutter head, a chute, a central column, a straight cutter head, a straight groove, a clamping block, an identification plate and an identification ring. The main drill shank of the present invention is provided with marking rings, the marking rings are distributed at even intervals, and the marking rings correspond to different depth markings. At the same time, the marking rings are set around, and the marking rings can also grasp the depth well during the rotation of the center drill. , which is conducive to the improvement of the precision of the thread processing process. There are symmetrical blocks on the drill shank, so that the blocks can fix the drill shank, avoiding the rotation deviation of the drill shank during use, and an inclined oblique knife is set on the drill bit. The head can cut and mill large-area materials, and a cross-symmetrical straight cutter head is set on the center column, which can improve the connection strength of the center cone, ensure sufficient strength and wear resistance while increasing the drilling speed, and increase the center drill life.