The invention discloses a suspension polymerization preparation method of a polystyrene/silica hydrated particle, and the method comprises the following steps: (1) surface modification of the silica hydrated: weighing a certain mass of silica hydrated to disperse in ethanol, adding a silane coupling agent for modification, processing the resulting solution by using stearic acid, and then separating the processed solution to put aside for standby use; and (2) synthesis of the polystyrene/silica hydrated particle, 1, dissolving a dispersant, 2, uniformly mixing the modified silica hydrated and styrene monomers, and subjecting the resulting mixture to ultrasonic dispersion; and 3, pouring an evocating agent into a dispersed styrene/silica hydrated suspension to mix uniformly, fast mixing the resulting mixture and the dispersant, and cooling and discharging after complete reaction polymerization to obtain the polystyrene/silica hydrated particle. By adopting the suspension polymerization preparation method provided by the invention, the inorganic mineral material of silica hydrated is compounded to the framework of the macromolecular styrene to improve the strength of the polystyrene particle.