Disclosed herein is a method for manufacturing a high-crush-strength iridium catalyst for hydrazine decomposition for spacecraft and satellite propulsion using bauxite, the method including: an acid treatment step of bringing bauxite into contact with a 0.1-10 M acid solution for 10-14 hr; a filtration step of filtering the acid-treated bauxite as a solid to remove the remaining acid and impurities; a thermal treatment step of bringing the filtered bauxite into contact with hot air at a temperature of 500-700.degree. C. for 2-6 hr; a catalyst loading step of loading an iridium catalyst onto the thermally treated bauxite; and a reduction step of reducing the catalyst of the catalyst-loaded bauxite.