Brain milling drill and mounting method thereof

The invention relates to a brain milling drill and a mounting method thereof. The brain milling drill comprises a drive mechanism, a cutter replacement mechanism arranged at one end of the drive mechanism, and a brain milling head protection frame replacement mechanism arranged at one end of the cutter replacement mechanism. The drive mechanism includes an integrated drive shaft, a milling drill head which is partially embedded into the front end of the drive shaft and is coaxial with the drive shaft, a first straight-tooth cylindrical gear which is integrally disposed at the tail end of the drive shaft, and a connecting shaft which is meshed with the first straight-tooth cylindrical gear. According to the brain milling drill of the invention, the drive shaft is of an integrated structure, which ensures coaxial drive and reduces noise and vibration; a straight-tooth cylindrical gear set is adopted to increase power and improve the drive accuracy; and the cutter replacement mechanism is convenient in replacement operation through ingenious combination of mechanical parts.