Bogie assembly, rail vehicle and rail system

The invention discloses a bogie assembly, a rail vehicle and a rail system, the bogie assembly comprises a bogie, and the bogie comprises a base; and the locking mechanism is arranged on the base, and the locking mechanism is suitable for locking or unlocking the bogie under the action of external force. Therefore, normal rotation of the rail vehicle during turning can be guaranteed, the rail vehicle can better turn conveniently, the problem that the rail vehicle swings due to the fact that the rail vehicle is affected by the uneven surface of the rail beam when going straight can be solved, and the running stability of the rail vehicle can be improved.