The invention relates to a preparation method for an aluminium alloy / borohydride hydrogen-production system. The system employs aluminium powder, a metal hydride and a metal salt as raw materials; aluminium alloy powder is obtained through ball-milling mixing, heating dehydrogenation fusion, cooling condensation and scraping collection, and then is mixed with a borohydride, and the mixture is subjected to tabletting for forming the aluminium alloy / borohydride hydrogen-production system, wherein the metal hydride is one of sodium hydride, calcium hydride, strontium hydride and sodium aluminium hydride, the metal salt is one of chlorine salts or nitrates of nickel, cobalt, iron, palladium, rhodium and platinum, aluminum accounts for 80-98.5% by mole of total aluminium alloy, the hydride accounts for 1-9% by mole of total aluminium alloy, and the metal salt accounts for 0.5-19% by mole. The preparation method is capable of improving the hydrolysis kinetics of aluminium / borohydride, and also improving the unit-mass hydrogen storage value of a hydrogenation system. The prepared aluminium alloy / borohydride hydrogen-production system has the advantages of being high in hydrogen storage value, convenient to carry, safe, reliable and the like, and has wide application prospect on portable hydrogen source application.