The invention provides a preparation method of a mesoporous SiO2/MoS2 material. The preparation method comprises the following steps: step I, weighing mesoporous silicon dioxide, a sulfur source and a molybdenum source according to a given ratio; step II, ultrasonically dispersing the mesoporous silicon dioxide, the sulfur source and the molybdenum source in an ethanol aqueous solution, and obtaining uniform turbid solution; step III, rotating and centrifuging the uniform turbid solution under a vacuum condition, and obtaining precipitates; step IV, transferring the precipitates into a stainless steel reaction kettle, adding polyethylene glycol, sealing, and reacting to obtain a reaction product; step V, washing the reaction product by using a neovaricaine aqueous solution, then washing with distilled water, and obtaining mesoporous silicon dioxide loaded with MoS2; step VI, adding silane coupling agent into the ethanol solution with the mesoporous silicon dioxide loaded with the MoS2 under a water bath condition, stirring, reacting, and centrifuging to obtain the amino modified mesoporous SiO2/MoS2 material; and step VII, dispersing the mesoporous SiO2/MoS2 material into an aqueous solution, adding activated polyethylene glycol, reacting, and obtaining the completely modified stable mesoporous SiO2/MoS2 material.