The invention discloses a power transmission system and a vehicle with the power transmission system. The power transmission system comprises an intermediate shaft, an engine, an electric power generator, an output shaft, and a first power switchover device. A duplex-tooth gear is sleeved on the intermediate shaft. The duplex-tooth gear is provided with two gear portions. The output end of the engine is arranged to selectively cooperate with one of the gear portions to transmit, so as to transmit power. The electric power generator is cooperated with the other gear portion to transmit, so as to transmit power. The output shaft is arranged to cooperate with the intermediate shaft to transmit. The first power switchover device is arranged to selectively join the duplex-tooth gear and the intermediate shaft, so that the duplex-tooth gear rotate synchronously with the intermediate shaft. The power transmission system can directly realize parking, and start and stop, and a starter motor is saved. In addition, an idling condition motor can drive the electric power generator to generate electricity, thereby improving engine thermal efficiency of the power transmission system, and cost and energy consumption are effectively reduced.