Drill bit capable of finely trimming drill hole

The utility model belongs to the technical field of drill bits, and particularly relates to a drill bit capable of finely trimming drill holes, which comprises a drill handle and a drill rod, and one end of the drill rod is connected with one end of the drill handle. A plurality of right-handed rotation cutting edges and a plurality of left-handed rotation cutting edges are sequentially and spirally arranged on the side face of the drill rod. The right-handed rotation blade is arranged at the other end of the drill rod; the rotation directions of the left-handed rotation cutting edges and the right-handed rotation cutting edges are opposite, and first grooves are formed between the right-handed rotation cutting edges; a second groove is formed between the left-hand blades; the width of the first groove is smaller than that of the second groove; the right-handed rotation cutting edge and the left-handed rotation cutting edge are both made of high-carbon steel materials. During drilling, the right-handed rotati