The invention relates to a treatment method of tail gas containing hydrogen chloride and solves the technical problems that existing treatment methods of tail gas containing hydrogen chloride are high in treatment cost and not ideal in treatment effect. The treatment method comprises steps as follows: a catalyst is added to a reaction kettle, glycerin is added, and the catalyst and glycerin are fully mixed under the slight stirring condition; byproduct gas containing hydrogen during hydrogen and potassium conversion of sulfonyl compound fertilizer sequentially passes through a foam remover, a first-stage or multi-stage condenser and a demister, foam , insoluble matter and vapor in the tail gas are trapped, separated and removed, and then the tail gas enters a buffer tank and is slowly sent into a reaction kettle after flow metering to react with glycerin; the reaction is performed under the homogenous stirring condition; after the reaction ends, dichlorohydrin is evaporated out through reduced pressure distillation and obtained. The treatment method can be applied to the treatment field of the byproduct gas containing hydrogen chloride during hydrogen and potassium conversion of the sulfonyl compound fertilizer.