An in-situ polymerization method was used in the preparation of a novel solid-phase microextraction（SPME） coating，where butyl methacrylate-ethylene glycol dimethacrylate（BMA-EDMA） was directly bonded to the surface of a modified stainless steel wire．Coupled with high performance liquid chromatography（HPLC），the prepared coating was applied in the extraction and determination of sudan Ⅰ,Ⅱ,Ⅲ dyes in fermented bean curd．The experimental conditions for SPME，including extraction time，desorption time and salt concentration were optimized．As a result,the linear relationships（r2≥0.923 2） between concentrations of 50 μg/L and 1 000 μg/L for sudan Ⅰ,Ⅱ,Ⅲ dyes were obtained.The limits of detection ranged from 0.303 μg/L to 1.808 μg/L．the run-to-run（n=3） and fiber-to-fiber（n=6） relative standard deviations of this method were no more than 9.2% and 16.5%,respectively.The spiked recoveries of three dyes were in the range of 79.5%-86.4%.The prepared stainless steel fiber possessed some advantages including high mechanical strength,simplicity,good stability and low cost.The method was fast and sensitive,and was suitable for the determination of sudan dyes in fermented bean curd.