The invention relates to a preparation method and device for powdery fatty acid methyl ester sodium sulfonate. The invention aims at providing the method capable of realizing the MES granularity basically identical to that of washing powder. The device has the characteristic of a simple and compact structure. The preparation method for powdery fatty acid methyl ester sodium sulfonate has the technical scheme that the preparation method for powdery fatty acid methyl ester sodium sulfonate is carried out according to the following steps that (1) water-containing MES materials are conveyed to an atomizer to be dried; (2) a powder body enters a cooling section, is cooled by cold air and is then discharged from the bottom of a tower; (3) a powdery fatty acid methyl ester sodium sulfonate product is obtained. The preparation device of the powder fatty acid methyl ester sodium sulfonate comprises a cyclone separator, a cloth bag dust remover and a drying tower, wherein the atomizer is arranged between a sedimentation section and a drying section; a plurality of hot air inlets are formed between the drying section and a cooling section; exhaust openings are sequentially communicated with the cyclone separator and the cloth bag separator; the bottom of the cooling section is provided with a cold air inlet; the bottom end of the cooling section is also sequentially communicated with a fluidized bed, a crushing machine and a powder cabin through pipelines.