The invention relates to the field of slow driving devices, and discloses a slow driving device for tooth alignment of a mechanical auxiliary tooth clutch in order to solve the technical problem that teeth of the clutch adopting the conventional large-size slow driving device are hard to align before the clutch is closed. The slow driving device comprises a motor (1), a shaft coupler (2), a reduction gearbox (3) and the tooth clutch (4) which are fixed on a rack (22) and are connected in series with one another in sequence, and further comprises a tooth alignment mechanism consisting of a fixed locating block (10) and a sliding locating block (11), wherein the fixed locating block (10) is arranged on the end surface of a first outer tooth sleeve (5); a column shaft (12) is arranged on the end surface of a second outer tooth sleeve (6) along the axial direction; the sliding locating block (11) is arranged on the column shaft (12) in a sleeving manner; and a plurality of locating teeth are arranged on the fixed locating block (10) and the sliding locating block (11). During tooth alignment, only a motor is needed to be inched to enable the locating teeth to be basically meshed, so that the inner and outer tooth sleeves can be in a meshed state; and the slow driving device is convenient to operate and can save the time.