The turboshaft engine power generation unit has attracted the attention of various researchers for its vital position in realizing more/all electric flying car concept. In this paper, a hybrid electric system that adopts a twin-shaft turboshaft engine power generation unit (TEPGU) architecture is studied. Based on operating conditions comparison, a power split mode is discussed, studying the characteristic laws of the TEPGU. In order to formulate fuel-economy-optimal power regulation strategies, a multi-dimensions-feature-projective searching method (MFPS method) are proposed. The formulated strategy is then compared and analyzed, with the fuel economy advantage of the power split strategy quantified. By validating through a land-to-air driving cycle of flying cars, the strategies demonstrate superior performance in fuel economy. Comparative results indicate that the strategies based on MFPS can achieve fuel consumption saving of 6.8% throughout the driving cycle, demonstrating significant advantages in low-power land conditions.