This paper proposes a new type of hybrid powertrain with a specially designed double-clutch transmission. Compared with the existing hybrid powertrains, the proposed solution with double-clutch transmission, based on innovative double-clutch and mechanical gear sets, has the potential to achieve higher levels of performance efficiency at a lower production cost. The impact factors of system efficiency are analysed on a dynamic non-linear simulation model. The control strategies of powertrain and the double-clutch transmission gear ratios are studied by simulation results. Additionally, the double-clutch transmission can increase the efficiency of regenerative braking.