Air conditioning system of railway vehicle and railway vehicle

The embodiment of the invention provides an air conditioning system of a railway vehicle and the railway vehicle. The air conditioning system comprises an air conditioning unit, the bottom of the air conditioning unit is provided with a rigid drainage outlet protruding downwards, and the air conditioning unit is used for being installed on the top of a vehicle body of the railway vehicle; a drainage hard pipe which is used for being vertically fixed to a vehicle body of the railway vehicle; a self-sealing elastic pipe which is sleeved and fixed at the upper end of the peripheral surface of the hard drainage pipe, and the self-sealing elastic pipe upwards protrudes out of the hard drainage pipe; when the air conditioning unit is installed on a vehicle body, the drainage outlet penetrates into the self-sealing elastic pipe and is tightly attached to the inner wall of the self-sealing elastic pipe, a gap is kept between the drainage outlet and the drainage hard pipe, and the gap between the self-sealing elastic