Low-floor rail transport transmission system breaks the monopoly on the key parts of rail transport transmission industry from foreign countries. The system adopts the transmission structural form of bevel gear together with cylindrical gear which has the advantages of compact structure, simple transmission mode, convenient assembly and high reliability. The gear uses splash lubrication to reduce the weight of the gear box and it is convenient to the maintenance meanwhile. The part locking device is also installed to improve the operational reliability. The compensation dosage of the output coupling is large, which could effectively buffer the vibration and impact from the rail and vehicle. Input coupling has the sliding function when the gear is overloaded, which could effectively protect the gear box and motor.