Oscillating tooth speed reducer of downhole power drill

The utility model discloses an oscillating tooth speed reducer of a downhole power drill. The oscillating tooth speed reducer comprises an upper joint, wherein a speed reducer shell is connected in a sealing manner to the lower part of the upper joint; a lower plug is connected in a sealing manner to the lower part of the speed reducer shell; a sealing cover is connected in a sealing manner at the lower part of the lower plug; the upper joint, the speed reducer shell, the lower plug and the inner part the sealing cover are communicated with each another; a shock wave tooth is arranged at partial inner wall of the speed reducer shell; an input shaft which rotates relatively is arranged in both the upper joint and the speed reducer shell through an input bearing string; the input shaft is provided with an eccentric shaft section; an output shaft which rotates relatively is arranged in the speed reducer shell, the lower plug and the sealing cover through an output bearing string; an oscillating tooth roller is arranged at the upper part of the output shaft; and the oscillating tooth roller is mutually engaged with both the eccentric shaft section on the input shaft and the shock wave tooth section inside the speed reducer shell. An input shaft alignment bearing which rotates relatively is arranged between the input shaft and the output shaft. A bearing fixing nut is fixedly arranged on the input shaft below the input shaft alignment bearing; and the bearing fixing nut is also fixedly connected to the inner ring of the input shaft alignment bearing.