The polyimidazolyl acetate ionic liquid (PAIL) was synthesized by Radziszewski reaction and coated on oxidized cellulose chromatography paper (Oxi-CFP) to obtain the thin film extraction paper (Oxi-CFP@PAIL). Then the Oxi-CFP@PAIL was used for the extraction of nonsteroidal antiinflammatory drugs (NSAIDs) in water. The structure of the Oxi-CFP@PAIL was analyzed by ATR-IR and TGA, results showed that the PAIL was successfully attached to the surface of the Oxi-CFP by chemical bonding. The SEM and AFM analysis also indicated that the PAIL was attached to Oxi-CFP, while its folding resistance was obviously improved. Moreover, the impacts of PAIL preparation conditions on the adsorption amount of Oxi-CFP@PAIL for 4 NSAIDs (tolmetin, ketoprofen, naproxen and diclofenac) were investigated, and the adsorption amount of Oxi-CFP@PAIL achieved the maximum amount for the target compounds when PAIL was prepared at 60 ℃ and 5% concentration was used, primarily PAIL has the highest content in cellulose filter paper.The Oxi-CFP@PAIL was used to extract the NSAIDs in the water containing carboxyl groups, and desorb with acetonitrile containing 1% formic acid and 1% 1 mol/L ammonium acetate. The extracting solution was then detected by HPLC-MS/MS. The recoveries for 4 NSAIDs were greater than 80%, and the limit of detection and limit of quantification for this analytical method was 0.02~0.10 μg/L and 0.07~0.33 μg/L, respectively.