Magnesium hydride (MgH₂) has been considered as a promising hydrogen storage material, but the pressing issues including sluggish kinetics and poor cyclic stability hampered its practical applications. Herein, a high-efficient catalyst comprising of YC_xF_y nanosheets-supported Ni nanoparticles (Ni₃₀/YC_xF_y) was designed and constructed aiming to resolve the abovementioned restrictions facing MgH₂. After hybridizing with Ni₃₀/YC_xF_y, the as-achieved MgH₂–10 wt.% Ni₃₀/YC_xF_y composite exhibits superior hydrogen desorption kinetics with an activation energy of 80.9 kJ·mol⁻¹ and a high capacity retention of 97.6% after 50 cycles. It is confirmed that the in situ formed Mg₂NiH₄ and YH₃ catalytic phases accelerate the hydrogen desorption kinetics, while the dispersed MgF₂ and carbon species prevent the crystallite growth, particle aggregation, and catalyst redispersion, contributing an excellent cyclic stability. This work provides a new strategy to synthesize efficient catalysts for hydrogen desorption of MgH₂.