The invention discloses an eccentric rolling type differential-tooth precision reducer which comprises an eccentric shaft, a bearing, an outer roller gear, a fixed inner gear and an output inner gear. The eccentric shaft is connected with the bearing, the outer roller gear is connected with the eccentric shaft through the bearing, the output inner gear and the fixed inner gear are respectively and movably connected with the outer roller gear, the bearing is composed of an inner ring, a roller body and an outer ring, and the inner ring is movably connected with the outer ring through the roller body. The eccentric rolling type differential-tooth precision reducer has the advantages that the outer roller gear on the eccentric shaft has the fixed inner gear and the output inner gear rolled and is large in reduction ratio, high in rotation precision, impact resistant, strong in rigidity, small in size, long in service life and the like.