The invention discloses a nano-magnesium-based hydrogen storage material for a high-energy solid battery. The weight percentage of the magnesium is 85-92%, the mass percent of the neodymium powder is4-8%, the mass percent of the yttrium powder is 1-5%, and the mass percent of the carbon matrix is 3-15%. Compared with an existing magnesium-based hydrogen storage material, the weight proportion ofthe components can ensure that the hydrogen storage content of magnesium is not reduced, meanwhile, the battery is more stable, and is more stable during charging and discharging; and the alloy is prepared through the method, the hydrogen absorption and desorption temperature of products can be greatly reduced, and the hydrogen absorption and desorption dynamics performance of the products can beimproved. The hydrogen absorption temperature of the magnesium-based hydrogen storage material can be reduced to 365K, and the magnesium-based hydrogen storage material can be completely released at the temperature of 501K, so that a substantial progress is obtained.