To address the critical impact of the hydrogen-oxygen ratio on the performance of hydrogen fuel cells，precise strategies are designed to enhance system energy conversion efficiency and battery life，thereby promoting their efficient application. Through mechanism analysis，the influence of the hydrogen-oxygen ratio on the electrochemical reactions and performance indicators of the fuel cells is clarified，and an optimal range for the hydrogen-oxygen ratio is determined. When deviating from this range，the battery performance will decrease; Build a dual loop ratio control system，with the main loop regulating the hydrogen flow rate and the secondary loop regulating the oxygen flow rate to achieve flow ratio matching. PID parameters are optimized using a combination of engineering tuning and intelligent algorithms，balancing system stability，accuracy，and response speed. The simulation model is built by using MATLAB to simulate different hydrogen-oxygen ratios and various disturbance conditions. The results showed that the oxygen flow rate could accurately track the hydrogen flow rate during steady-state operation of the system，and the flow ratio error was controlled within a very small range. In the face of disturbance，the oxygen flow rate could quickly recover to the set ratio，and the power fluctuation amplitude was small and the adjustment time was significantly shortened. When the hydrogen-oxygen ratio is optimal，both the power output and energy conversion efficiency of the fuel cell stack are significantly improved，and the battery life is extended.