<p>To thoroughly elucidate the intrinsic mechanisms by which electrical pulse treatment regulates microstructure and properties, this study systematically designed comparative experiments with varying effective durations and duty cycles. The results indicate that moderate pulsed currents synergistically exert thermal and non-thermal effects, effectively promoting static recrystallization and grain refinement in AZ31 magnesium alloy while accelerating the dissolution of the β-Mg₁₇Al₁₂ phase. This process thereby reduces the hindrance to dislocation motion in the secondary phase. However, excessively prolonged exposure times or high duty cycles may induce abnormal grain growth, thereby diminishing the strengthening effect of fine-grained structures. Under optimized parameters of 30% duty cycle and 300-s duration, the alloy’s elongation increased significantly by 87%, with tensile strength reaching 194&#xa0;MPa, achieving synergistic enhancement of strength and ductility. This study demonstrates that precisely controlling electrical pulse parameters to synergistically optimize grain size and second-phase dissolution behavior is an effective approach for enhancing the comprehensive properties of AZ31 magnesium alloys, providing crucial theoretical support for the industrial production of high-performance magnesium alloys.</p>