The invention relates to a preparation method of vinyl sulfate. The preparation method comprises the following steps: adding ethylene glycol into a reaction kettle A filled with a halohydrocarbon solvent, uniformly stirring, dropwise adding thionyl chloride to carry out a substitution reaction, removing hydrogen chloride by reduced-pressure distillation, then, washing a reaction solution to be neutral by using a saturated sodium bicarbonate solution, standing still, and skimming to obtain a glycol sulfite halohydrocarbon solution; adding the glycol sulfite halohydrocarbon solution into a reaction kettle B, adding monopotassium phosphate or sodium tungstate as a catalyst, regulating the pH by using a sodium bicarbonate aqueous solution, and adding a sodium hypochlorite aqueous solution to carry out an oxidation reaction; at the end of the reaction, skimming to obtain a vinyl sulfate halogenated alkane solution, carrying out concentration, then, adding n-hexane to carry out recrystallization, and carrying out filtration to obtain high-purity vinyl sulfate. By using the preparation method, raw materials are available, the price of the catalyst is low, the product is easy to purify, and the obtained product is low in acidity, low in water content, high in purity and suitable for large-scale production.