Introduction to the Results: Fuel cells are a clean and efficient power source for vehicles, capable of generating electrical energy through hydrogen-oxygen catalytic reactions to drive electric motors and charge the power battery. This technology represents the direction of future development in clean automotive power systems. Currently, international renowned automobile companies such as Toyota from Japan and Hyundai from South Korea have achieved marketization of fuel cell vehicles, while Japanese Honda, American General Motors, and German Daimler have also proposed concrete marketization plans. China's new energy vehicle "three verticals and three horizontals" strategy clearly lists fuel cell vehicle technology as one of the three major types of automobiles. Against the backdrop of an accelerated process of international fuel cell vehicle marketization, in order to seize the technological high ground, China's fuel cell vehicle onboard multi-energy source control technology bottleneck urgently needs to be resolved. This project originates from preliminary theoretical research and practical engineering problems arising from cooperative projects with Shanghai Volkswagen Automobile Company. The research will focus on the extended-range fuel cell power system to investigate the mechanisms, transmission paths of time delay characteristics in fuel cells, and their impact on the instantaneous optimization energy management strategy for multiple energy sources in the entire vehicle. The goal of the study is to propose an instantaneous optimization energy management scheme considering the time delay characteristics of fuel cells based on the elucidation of the mechanism, thereby further improving the fuel economy of the entire vehicle. The theoretical significance of the topic lies in revealing the causes and impacts of the time delay characteristics of fuel cell extenders from a mechanistic and pathway perspective, while the practical application value lies in providing a reference example for the optimization design of energy management strategies for extended-range fuel cell vehicles, and promoting the development of fuel cell vehicle design technology in China.