Through the analysis of the characteristics of fuel cells, the main research for vehiclemounted fuel cell power electronics converter was given. Through the optimization of the topology of the Boost converter, the improvement of the efficiency and the improvement of the control method, the design of an efficient and reliable converter suitable for the fuel cell with a large voltage conversion ratio was designed. Through experimental tests, it was proved that the converter could realize stable output operation of the fuel cell, effectively protect the fuel cell, further prolong the life of the fuel cell, and prevent the battery characteristics from being lowered.