The invention discloses a preparation method of a 
silodosin intermediate and relates to the technical field of 
chemical synthesis of drugs. The preparation method comprises the following steps: subjecting salicyaldehyde and 
ethylene carbonate to 
transesterification to obtain 2-(2-hydroxyethoxy)
benzaldehyde; then, carrying out a Dakin oxidation reaction to obtain 
sodium 2-(2-hydroxyethoxy) 
phenol;then, subjecting 
sodium 2-(2-hydroxyethoxy) 
phenol and trifluoroethanol to an etherification reaction to obtain 2-[2-(2,2,2-trifluoroethyoxy)phenoxy]ethyl 
alcohol; and finally, subjecting 2-[2-(2,2,2-trifluoroethyoxy)phenoxy]ethyl 
alcohol and 
methanesulfonyl chloride to an esterfication reaction to obtain the 
silodosin intermediate 2-[2-(2,2,2-trifluoroethyoxy)phenoxy]
ethyl methanesulfonate. The preparation method is novel and short in synthesis 
route, and a target product can be prepared by only four-step reaction. Both raw materials and reagents used for preparation are cheap, available andenvironment-friendly, all the 
reaction conditions are mild and controllable, the preparation method is convenient and simple in operation, and the prepared 
silodosin intermediate is high in purity andyield, suitable for industrial production and wide in prospect and industrial application value.