The phase structure and electrochemical characteristics of CeMn0.25Al0.25Ni1.5+x (x=0.0, 0.3, 0.5, 0.7, 0.9, 1.1) alloys with Ni overstoichiometric addition were studied. XRD, SEM and electrochemical testing have revealed that all alloys mostly contain hexagonal CeAl phase and cubic CeNi phase, and the grain size of the alloys becomes larger with increasing Ni content. The electrochemical activity of CeMn0.25Al0.25Ni1.5+x alloys has been greatly improved by Ni overstoichiometric addition and the discharge capacity can increase from 118.3 mAh·g-1 (x=0.0) to 200.7 mAh·g-1 (x=1.1) at 298 K and from 170.4 mAh·g-1 (x=0.0) to 271.4 mAh·g-1 (x=0.9) at 338 K, respectively. The P-C-T curves show that the slopes of equilibrium hydrogen pressure plateau of CeMn0.25Al0.25Ni1.5+ x (x=0.0, 0.3, 0.5, 0.7, 0.9, 1.1) alloys become flatter, longer and higher with increasing Ni content, and therefore this may be the key factor that enhances the discharge capacity of the alloys. CeMn0.25Al0.25Ni2.4 alloy is a kind of candidate anode material for MH-Ni with further optimizing compositions.