The invention relates to a method for preparing antidepressant fluoxetine, and belongs to the method for preparing a medicinal compound. The technical scheme in the invention comprises the following three steps of aminolysis, catalytic hydrogenation and aromatic etherification reaction, wherein the three steps are performed in one pot without separation. In the method, the conventional chemical reduction method is replaced by the catalytic dehydration process, and the used reducing agent is hydrogen gas, so that the environmental pollution is reduced; the methylamine is gaseous methylamine, so that the reaction conversion rate is improved, and other substances, such as water and the like, are prevented from being introduced into a reaction system; and p-chlorobenzotrifluoride is added dropwise in the etherification reaction, so that the reaction speed can be conveniently controlled, the yield of a target product is improved, and the possibility of catalyst poisoning is reduced.