In order to enhance the fuel economy of hybrid electric vehicles, this paper proposes a novel method for the design and analysis of hybrid electric vehicle powertrain configurations. Initially, by analyzing the energy transformation of hybrid electric vehicle, the single-mode configurations are designed by considering the engine efficiency, the conversion energy loss, and the mechanical transmission efficiency, respectively. Then, two novel multimode configurations with single electric machine are obtained through integrating the single-mode configurations. In addition, performance comparison and analysis between the two novel configurations and the improved version of Toyota Prius under Highway Fuel Economy Test and Urban Dynamometer Driving Schedule cycles are conducted. The results indicate that the two novel configurations possess better fuel economy than the improved version of Toyota Prius.