The invention discloses a hybrid power system integrated by a double-clutch automatic gearbox with a motor. A first clutch and a second clutch control a first input shaft and a second input shaft to be disengaged from or combined with an engine output shaft correspondingly; a first intermediate shaft and a second intermediate shaft transmit the power coming from the first input shaft and the second input shaft to a gearbox output shaft; speed changing of multi-shift gear sets between the two input shafts and between the two intermediate shafts is achieved; and the motor integrated on the double-clutch automatic gearbox is installed outside a gearbox shell body, an output gear of the motor is located in the gearbox shell body and is constantly engaged with a driven gear of one of the shifts, the driven gear is arranged on the first intermediate shaft or the second intermediate shaft, and integration arrangement and power connection of the motor and the double-clutch automatic gearbox are achieved. The hybrid power system has a plurality of working modes such as the pure electric mode, the engine individual driving mode, the engine and motor joint driving mode, the travelling charging mode, the braking energy recovery mode, the engine parking starting mode and the engine traveling starting mode.