Abstract: To address performance degradation caused by liquid-water accumulation in a dead-ended proton exchange membrane fuel cell (PEMFC) at high current density, tail-purge parameter effects and control strategies were investigated. Through numerical simulations, the effects of different purge parameters at 1.5 A/cm²—including purge triggering time, purge duration, and purge stoichiometry—on voltage recovery and energy efficiency were examined. The results show that when purge stoichiometry was 2.5, increasing purge duration from 1 s to 3 s improved voltage recovery rate from 99.12% to 99.88%; when purge duration was 1 s, increasing purge stoichiometry from 1.5 to 2.5 raised energy efficiency from 15.37% to 25.77%. To further enhance energy efficiency, a water-saturation-based purge control strategy (threshold: 40%) was proposed, achieving an efficiency of 37.13%. These findings provide theoretical support for parameter optimization and control strategy development to enable long-term stable operation of dead-ended PEMFCs.