The utility model relates to a soil layer or rock stratum creep into component technical field, disclose a core drill, in the inside jump ring chamber of having seted up of drill bit crown to the portion is equipped with the jump ring at the jump ring intracavity, and the tip is taperedly under the drill bit crown. Cutting teeth fixed connection is in the cutting face of drill bit crown, and the cutting teeth includes: alloy basic unit and diamond layer, alloy basic unit and diamond layer fixed connection, the diamond layer is in cutting edge one side of drill bit crown, and alloy basic unit is fixed with the laminating of drill bit crown. The utility model discloses a core drill bottom is the taper surface, has played the effect that the drilling tool is stabilized in centering in the use, has reduced the swing and the impaired probability of drilling tool of drilling tool.