The leaching process of magnesiothermic self-propagating product generated during the multistage deep reduction process was investigated. The influence of magnesiothermic self-propagating product particle size, HCl solution concentration, and leaching solution temperature on the leaching behavior of Al and V elements was investigated. Results demonstrate that the leaching rate of Al and V is increased with the rise in leaching solution temperature, the increase in HCl solution concentration, and the enlargement of magnesiothermic self-propagating product particle size. The leaching processes of Al and V are consistent with the chemical reaction control model. When the magnesiothermic self-propagation product with D₅₀ of 59.4 μm is selected as the raw material, the leaching temperature is 40 °C, and 1 mol/L HCl solution is employed, after leaching for 180 min, the leaching rates of Al and V are 24.8% and 12.6%, respectively. The acid-leached product exhibits a porous structure with a specific surface area of 3.5633 m²/g.