The application discloses a self-adaptive tooth entering transition device, a rack rail track and a
transition system. The self-adaptive tooth entering transition device comprises a transition section, which is arranged in front of a rack rail section and is used to drive a
train gear to rotate to the same linear speed as a
train steel wheel. Before the
train enters the rack rail from the general rail, the train gear is driven to rotate in advance in the transition section, and the linear speed of the train gear is made to be the same as the linear speed of the train steel wheel. When the train enters the rack rail section, the direct engagement with the rack rail can be realized, so that the
impact and abrasion of the rack rail section during the tooth entering are avoided, the efficiency and stability of the rack rail vehicle when entering the rack rail section are improved, and the self-adaptive tooth entering transition device has important popularization significance.