A novel method of high performance liquid chromatography coupled with oxidized sepiolite（O-Sep） based solid phase extraction（SPE） was developed for the analysis of sulfonamides in environmental water samples.The O-Sep was successfully synthesized by acid treatment,then packed into a homemade PEEK micro column,which had a high adsorption capacity towards sulfameter（SMD）,sufladoxine（SDX） and sulfaphenazole（SPP）,and the corresponding saturated extraction amounts of 10 mg O-Sep were 203.2,150.3 and 102.1 ng,respectively.The calibration curves of SMD,SDX and SPP showed good linear relationships in the range of 1.0-50.0 μg/L,with their detection limits of 0.3-0.5 μg/L and relative standard deviations（RSDs） not more than 5.0%.The method was applied in the simultaneous analysis of three analytes with satisfactory recoveries,which were 79.5%-98.3% for tap water,74.3%-98.6% for river water and 70.2%-98.7% for rain water with RSD of 1.4%-7.6%.This method was simple,sensitive and accurate,and showed a great potential in the determination of trace sulfonamides in environmental samples.