The invention discloses a preparation method of composition for alpha-sulfo-group fatty acid alkyl ester salt-containing detergent, and the preparation method comprises the following steps of: spraying a non-ionic surface active agent onto powdery alpha-sulfo-group fatty acid alkyl ester salt in the manner of spraying, spraying and stirring to be formed into a compound of the non-ionic surface active agent and the powdery alpha-sulfo-group fatty acid alkyl ester salt and formed into a layer of liquid non-ionic film-packed layer on a surface; and adding zeolite, and evenly mixing into the composition for detergent. The flowability of the composition for the detergent prepared by the method is obviously higher than that of the alpha-sulfo-group fatty acid alkyl ester salt per se, the detergent is hard to bond to be clustered, and is stable in property, the requirement of the stable discharge in a production technology can be met, and the generation of the bad smell when the alpha-sulfo-group fatty acid alkyl ester salt-containing powdery detergent is stored can be effectively restrained.