The invention relates to a method for preparing calcium ferroaluminates. The method comprises the following steps: proportionally mixing an aluminium nitrate hydrate, a calcium nitrate hydrate, a ferric nitrate hydrate, hexamethylenetetramine, acetylacetone, deionized water and the like uniformly by a sol-gel method, then stirring the mixture at the temperature of 50-70 DEG C to obtain sol, ageing the sol to form gel, carrying out heat treatment on the gel at the temperature of 750-800 DEG C for 2-4 hours and slowly cooling the gel to the room temperature, thus obtaining the calcium ferroaluminates. Compared with the prior art, the method has the following advantages: the preparation process is simple; the reaction process is easy to control; and the product has high uniformity and purityand can be fired at the temperature lower than the temperature in the traditional methods.