The invention provides a series / parallel double-motor and two-clutch hybrid electric drive unit for a vehicle, comprising a main drive motor, an integrated starter-generator, a compensating gear, a principal axis, a first-level reduction gear, a main clutch and a first clutch, wherein the main drive motor is connected with the first-level reduction gear by the first clutch. The invention also provides a series / parallel double-motor and tri-clutch hybrid electric drive unit for the vehicle, which comprises a second clutch and a second-level reduction gear on the basis of the double-motor and two-clutch hybrid drive unit. In the hybrid electric drive unit of the invention, the inner structure has compact layout and the inner connection is high efficient and reasonable; the hybrid electric drive unit of the invention can realize switch of connection and disconnection between each hybrid power source and wheels and achieves switch between operating modes and gears for a hybrid power-driven system by switching power output torque.