The invention discloses a preparation method of a 
hydrogen storage 
alloy material. A 
structural formula of the material is ABx(x=3.0-3.5), wherein a chemical constituent of an element on A side is Lz1-yMgy, and y is 0.25-0.33; and B is NipCoz (Mn Al3)w, p is 2.5-3.3, z is 0-0.5, and w is 0-0.1. The preparation method comprises the following steps of: (1) adopting 
oxalic acid-
ethanol solution as a precipitator, taking 
saline solution of 
rare earth, 
magnesium, 
nickel and various doped 
metal as raw materials, preparing a precipitate, and washing, filtering, 
drying and firing the precipitate to obtain an 
alloy oxide precursor; and (2) taking 
calcium hydride as 
reducing agent, and high-purity 
hydrogen as 
reducing atmosphere, carrying out reduction in a vacuum / 
atmosphere tubular furnace, and rinsing, soaking, washing and 
drying the reduzate to obtain 
hydrogen storage 
alloy powder. According to the preparation method, the 
rare earth oxide and 
metal salt are adopted as the raw materials, so that the adoption of expensive pure 
metal is avoided, the cost can be obviously reduced, the prepared alloy 
powder has mall 
granularity, the compositions are uniform, the 
discharge capacity is high, the performance is stable, and the 
hydrogen storage alloy material can be used as a negative active material of a large-power 
nickel-hydrogen battery.