Ga₂O₃ is considered a potential anode material for next-generation lithium-ion batteries due to its high theoretical capacity and unique self-healing capability. To develop a novel preparation method and in-depth understanding of the electrochemical reaction mechanism of Ga₂O₃, a brand-new liquid-liquid dealloying strategy was exploited to construct porous α-Ga₂O₃ nanowire networks. Profiting from the well-designed porous structure, the material exhibits impressive cycling stability of a reversible capacity of 603.9 mA·h/g after 200 cycles at 1000 mA/g and a capacity retention of 125.2 mA·h/g after 100 cycles at 0.5C when assembling to Ga₂O₃//LiFePO₄ full cells. The lithiation/delithiation reaction mechanism of the porous Ga₂O₃ anodes is further revealed by ex-situ Raman, XRD, TEM measurements, and density functional theoretical (DFT) calculations, which establishes a correlation between the electrochemical performance and the phase transition from α-Ga₂O₃ to β-Ga₂O₃ during cycling.