Preparation method and device of benzyl carbazate

A preparation method of benzyl carbazate relates to the field of synthesis of benzyl carbazate, and comprises the following steps: solution preparation: dissolving a proper amount of hydrazine hydrate in a proper amount of dichloromethane, adding a proper amount of a catalyst, and uniformly stirring to obtain a precondensation solution; condensation reaction: introducing a proper amount of benzyl chloroformate into the uniformly stirred precondensation solution for condensation reaction to obtain a layered liquid phase; performing liquid phase separation: performing liquid separation on the layered liquid phase to obtain crude benzyl carbazate and a hydrazine hydrate solution containing hydrazine hydrochloride; the hydrazine hydrate solution containing hydrazine hydrochloride and a proper amount of neutralizer are subjected to a neutralization reaction and then recycled and reused; refining the product: refining the crude benzyl carbazate to obtain the product benzyl carbazate; a hydrazine hydrate solution wi