Earth-abundant metal oxides are usually considered as stable but catalytically inert toward hydrogen evolution reaction (HER) due to their unfavorable hydrogen intermediate adsorption performance. Herein, a heavy rare earth (Y) and transition metal (Co) dual-doping induced lattice strain and oxygen vacancy stabilization strategy is proposed to boost CeO2 toward robust alkaline HER. The induced lattice compression and increased oxygen vacancy (Ov) concentration in CeO2 synergistically improve the water dissociation on Ovsites and sequential hydrogen adsorption at activated Ov-neighboring sites, leading to significantly enhanced HER kinetics. Meanwhile, Y doping offers stabilization effect on Ov by its stronger Y─O bonding over Ce─O, which endows the catalyst with excellent stability. The Y,Co-CeO2 electrocatalyst exhibits an ultra-low HER overpotential (27mV at 10mA cm-2) and Tafel slope (48mV dec-1), outperforming the benchmark Pt electrocatalyst. Moreover, the anion exchange membrane water electrolyzer incorporated with Y,Co-CeO2 achieves excellent stability of 500h under 600mA cm-2. This synergistic lattice strain and oxygen vacancy stabilization strategy sheds new light on the rational development of efficient and stable oxide-based HER electrocatalysts.