Abstract: For solving the problem that the ISG single-axis parallel hybrid energy recovery system is low efficiency, a structure with double-clutch and high power electric motor was designed. According to the theoretical of vehicle dynamics, the power demand in driving cycle for typical cities in China was calculated. Base on the stable conditions, simulation of the power and transmission conditions of the new power system was carried out, test results showed that the power and economy could achieved state switching process without torque ripple, and the smoothness of power delivery was improved, the time of transition conditions was shorten (reduced from 8 s to 4 s), fuel economy and emission performance also were improved.