The invention relates to the field of metal materials, in particular to a high-strength magnesium alloy capable of quickly reacting with media and a preparation method thereof. The high-strength magnesium alloy capable of quickly reacting with media is prepared from the following components: gadolinium, yttrium, aluminum, zinc, zirconium, rhenium, silicon, copper, iron, nickel, gallium, indium, beryllium, calcium and magnesium. Mixed reaction promoting elements (MRAE) including Si, Ni, Ga, In and the like are added to a magnesium alloy, and the continuity of magnesium hydrate can be damaged byphases formed by the elements and magnesium during reaction of magnesium and media, so that the effect that the reaction of magnesium and media is promoted is achieved; the proportion of all elementsin magnesium alloy is adjusted and controlled, so that the reaction rate of magnesium alloy and media is adjusted, thus, the controllable range is wide, additionally, the magnesium alloy material hasflexibility, and therefore, the magnesium alloy satisfies the application requirements of the industrial field.