The invention relates to the technical field of EPS foam production, and discloses a preparation method of an EPS foam product. The EPS foam product comprises the following components: 60-70 parts of polystyrene particles, 20-25 parts of benzene, 60-70 parts of absolute ethyl alcohol, 20-22 parts of glycol ether, 8-10 parts of soluble pentane and 5-6 parts of brominated polystyrene. The preparation method comprises the following steps: S1, foaming; S2, curing; S3, forming; and S4, cutting. The material is composed of the polystyrene particles, the benzene, the absolute ethyl alcohol, the glycol ether, the soluble pentane and the brominated polystyrene, the polystyrene particles are composed of sodium dodecyl benzene sulfonate, polyvinyl alcohol, calcium phosphate, styrene, auxiliaries and calcium carbonate, and therefore, the product has excellent tensile resistance, shear resistance, bending resistance and compression resistance; and in the using process of the product, the product is not easy to damage due to external force, long in service life, large in linear elasticity change range, good in elastic property and capable of bearing large pressure.