The invention provides a rail vehicle traction system and a rail vehicle. The rail vehicle traction system includes a natural gas traction system and an electric traction system, the output end of thenatural gas traction system and the output end of the electric traction system are connected with the input end of a traction drive system, the output end of the traction drive system is connected with a traction motor, and the traction motor is used for providing power for rail vehicles. According to the railway network environment, the rail vehicle can select a suitable traction mode, and underthe work condition without contact networks, power is provided for the rail vehicles by using the natural gas traction system; under the work condition with the contact networks, power is provided for rail vehicles by using the traction drive system, and the rail vehicle can thus be suitable for electrified railways and non-electrified railways at the same time.