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 YCxFy nanosheets-supported Ni nanoparticles (Ni30/YCxFy) was designed and constructed aiming to resolve the abovementioned restrictions facing MgH2. After hybridizing with Ni30/YCxFy, the as-achieved MgH2–10 wt.% Ni30/YCxFy 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.