Effect of TiF3 addition as the catalyst on the hydrogen desorption property of Mg95Ni5 composites by hydriding combustion synthesis (HCS) was investigated. Addition of 1% TiF3 (molar fraction) can get the best hydrogen desorption property for Mg95Ni5 mechanically milled for 10 h, which could desorb 5.20% (mass fraction) of H2 in 1800 s at 523 K. The apparent activation energy of hydrogen desorption for Mg95Ni5+1%TiF3 milled for 10 h was decreased to 86 kJ/mol from 124 kJ/mol of Mg95Ni5. Results show that catalytic effect of TiF3 could be attributed to the formation of MgF2 and Tix+ hydrides which destabilize the bonding of Mg-H.