V_{100 - x} Cr _x (x = 8 or 10, atomic fraction, %) hydrogen-separation alloys undergo cracks during cold rolling and are difficult to be shaped via room temperature processing. However, the addition of rare-earth element Y can greatly improve their cold-rolling plastic deformation ability, facilitating the low-cost fabrication of V-based alloy membranes for hydrogen separation with high flux on a large scale. In order to achieve both high hydrogen-permeation efficiency and service life, insight into the hydrogen permeability and hydrogen-embrittlement resistance is required on the basis of excellent cold-rolling formability. In this work, the effects of Y addition on the microstructure, cold-rolling formability, hydrogen permeability, and hydrogen-embrittlement resistance of as-cast V_{100 - x - y} Cr _x Y _y (x = 8, y = 1; x = 10, y = 0, 1, 3) hydrogen-separation alloys were studied using an oxygen-nitrogen-hydrogen analyzer, a cold-rolling machine, a hardness tester, a tension machine, and a hydrogen-permeation device as well as via XRD, SEM, TEM, and EPMA. In addition, the causes of the embrittlement of the V_{100 - x} Cr _x alloys and plasticization mechanism of V-Cr-Y alloys were explained. The microstructure formation and hydrogen-embrittlement resistance of V-Cr and V-Cr-Y alloys were also analyzed. Results showed that V-Cr alloys show a single-phase equiaxed grain microstructure, while V-Cr-Y alloys show a composite microstructure comprising a dendritic solid solution and secondary-phase particles located in the inter-dendritic region. The addition of Y in binary V-Cr alloys remarkably reduces the hardness, thereby greatly improving cold-rolling formability. Among the V₉₁Cr₈Y₁, V₈₉Cr₁₀Y₁, and V₈₇Cr₁₀Y₃ alloys, V₉₁Cr₈Y₁ showed the lowest hardness (108.88 HV) and highest maximum cold-rolling reduction rate (94.5%). Although the hydrogen permeability of the V-Cr-Y alloys was lower than those of Y-free alloys, it was still 2.5-3.0 times higher than those of commercial Pd₇₇Ag₂₃ alloys. Moreover, the V-Cr-Y alloys showed much better hydrogen-embrittlement resistance than those of V-Cr alloys and could be slowly cooled to room temperature without rupture. Rare-earth metal Y as a scavenger could react with O and S to form secondary-phase particles, exerting a purification effect, which softened the matrix and reduced the resistance of alloys to plastic deformation. Thus, high-performance V-Cr-Y alloy membranes with an excellent combination of formability and hydrogen-embrittlement resistance were prepared.