The invention relates to a preparation method of an aluminium alloy profile and belongs to the field of alloy preparation. According to the preparation method, firstly, ferrous chloride is used as a raw material, sodium hydroxide is dropwise added in a certain environment, granular ferrous hydroxide is produced, then aluminium powder is sprayed to surfaces of the granular ferrous hydroxide, oxygen is introduced during combustion of a magnesium ribbon, and finally, the aluminium alloy profile can be prepared through reduction reaction, extrusion molding, quenching and drying. The preparation method has the beneficial effects as follows: due to the uniformity of the internal structure and refinement of grains of an aluminium alloy wire prepared with the method, the quality and properties of the aluminium alloy profile are greatly improved, the tensile strength of the aluminium alloy profile is higher than 560 N/mm<2>, and the elongation is in a range of 18-22 A.