A series hybrid system with a storage battery as the main driving power source and a solid oxide fuel cell (SOFC) as an auxiliary power source was designed and the parameter matching of key components was then conducted based on complex and variable boundary conditions. The simulation of SOFCbattery hybrid power system and comparison with the prototype electric vehicle were carried out with the Advisor software from the view of lightweight design. The results show that the designed hybrid system can meet the vehicle power and economy requirements and compensate for the disadvantages of short mileage and poor endurance of electric vehicle. Meanwhile, it reduces the peak power demand of battery system and prolongs the battery life. According to the analysis of driving mileage, the designed hybrid system can reach the expected 600 km target, which shows the potential of SOFC in the future transportation field.