Disclosed is a trephine drill for an implant. The trephine drill for the implant includes: a perforating body which comprises a first end part provided with a cutter for perforating the alveolar bone and a second end part formed with a through hole and a rod body which couples with the perforating body to move close to and apart from the first end part of the perforating body toward the through hole of the perforating body and adjusts a perforation depth when perforating the alveolar bone. With this, not only an alveolar bone is precisely perforated at a preset depth, but also an alveolar bone piece, generated when perforating the alveolar bone, is easily removed from inside of a perforating body.