The invention relates to a separation method of oil-water emulsion. The separation method comprises the following steps: carrying out freezing polymerization reaction to uniformly mix polyethylene glycol diacrylate, polydivinylbenzene particles and an initiator in a solvent; after introducing nitrogen gas to remove oxygen, transferring into an injector and sealing; controlling the reaction temperature to be -18 DEG C and reacting for 48 hours; after sufficiently washing an obtained product through an eluting solvent, carrying out oil-water emulsion separation on the product only under the action of gravity, wherein the oil-water separation efficiency can reach 99.8 percent, the oil content in water is less than 50ppm and the adsorption capacity of a polymer material on the oil-water emulsion is higher than 2.8g/g. The preparation method provided by the invention is simple and reliable and post-treatment is simple; an obtained material is used for separating the oil-water emulsion and has the advantages of rapid separation speed, high separation efficiency, good repeated utilization rate and great adsorption capacity.