The invention provides a preparation method of a porous hydrophobic oleophylic sponge. The method comprises the steps: taking polymer foams, placing in a heating furnace, under the protection of inert gas, heating up to 150-1000 DEG C, calcining for 0.2-10 h, and thus obtaining the porous hydrophobic oleophylic sponge. The porous hydrophobic oleophylic sponge obtained by the method adsorbs oil, does not adsorb water, can adsorb the oil or organic matters which are hundreds of times heavier than the sponge, and has good toughness; and after the oil or organic matters are adsorbed, the adsorbed oil or organic matters can be removed through extrusion, distillation, burning and other methods, and thus the porous hydrophobic oleophylic sponge can be used repeatedly. The preparation method is simple, needs no complicated chemical reactions or material preparation processes, and has the advantages of convenient operation, good repeatability and easily industrialized implementation. The porous oil-adsorption sponge has the characteristics of large specific surface area, low density, good flexibility, hydrophobic oleophylic performance and the like, can be used for oil-water separation, and has good application prospects in the fields of wastewater treatment, adsorption of leaking crude oil or organic matters and the like.