The invention relates to a method for preparing anti-rust paint for treating the surface of a steamship. The anti-rust paint is prepared from the following components: zinc powder, methyl ethyl ketone, alkyd resin, methacrylate, sodium tripolyphosphate, polymer polyol glycerin ether defoaming agent, hexanediol butyl ether acetate, triethylene diamine, glycerol, mixed tung oil, dimethylbenzene, dicumyl peroxide, silane coupling agent KH792, triallyl cyanurate, maleic anhydride, styrene, p-benzoquinone and p-tert-butylcatechol. The anti-rust paint for treating the surface of a steamship is wide in raw material sources and low in cost, the compatibility among the components can be improved due to addition of the film forming resin in the prescription, the film forming effect is greatly improved; the component prescription has strong adhesion, high hardness, scratch resistance, acid-alkali resistance, water resistance, oil resistance and excellent anti-rust performance to a metal surface, the painted film has high drying speed under a natural condition, and the service life of the painted film can be 8-10 years.