Abstract: In view of the defects of heavy pollution, high operation and maintenance costs, and large safety hazards of traditional backup power supply in communication rooms and data centers, this paper establishes a refined electrochemical model of proton exchange membrane fuel cell (PEMFC) with triple polarization loss, introduces Henry"s law to correct oxygen concentration and constructs a dynamic internal resistance formula, relying on MATLAB simulation quantifies the impact of load fluctuations on battery output characteristics. Simulation shows that when the temperature and voltage remains unchanged, the energy potential is constant, the polarization loss increases with the increase of current, and the load increases to reduce the battery efficiency. PEMFC dynamically responds quickly and runs stably. Combined with domestic and foreign engineering cases, we prove its feasibility as a communication backup power supply from the perspective of performance, economy, operation and maintenance, and industrialization: PEMFC power generation efficiency is 85%~90%, and modular redundancy can ensure uninterrupted power supply. Compared with diesel units, it is green, low-noise and simple operation and maintenance; however, the cost of precious metal catalysts, hydrogen energy Insufficient support and lack of industry standards limit its large-scale application. The model in the article can provide theoretical support for the design of communication fuel cell power controller, and the research conclusion provides engineering reference for the backup power supply construction of green data centers.