Preparation method of 1, 3-propane sultone

The invention discloses a preparation method of 1, 3-propane sultone. The invention relates to a preparation method of 1, 3-propane sultone, which comprises the following steps: (1) taking 1, 3-propylene glycol and concentrated hydrochloric acid as raw materials, reacting under the action of a catalyst, and distilling out a fraction at 50-60 DEG C, namely 3-chloro-1-propanol; (2) sequentially adding a sulfonating agent and water into the 3-chloro-1-propanol for sulfonation reaction, dropwise adding concentrated hydrochloric acid into a solid obtained after water removal to adjust the pH value, introducing hydrogen chloride gas into a filtered liquid for acidification to obtain a 3-hydroxy propanesulfonic acid crude product, adding the 3-hydroxy propanesulfonic acid crude product into a water-carrying agent for azeotropic purification, and filtering to obtain the 3-hydroxy propanesulfonic acid. Extracting a residual base solution after azeotropy by using ethyl acetate, and concentrating to obtain a pure produc