Non-steroidal anti-inflammatory drugs,are one of the most widely used pharmaceutically active compounds in veterinary medicine.Dispersive liquid-liquid microextraction(DLLME) is a mini-extraction technique with merits of low cost,environment friendliness and high extraction efficiency.Moreover,this method is easy to operate and requires only a short operation time.In this paper,a deep eutectic solvent(DES) based on choline chloride was used for the first time as the liquid-liquid microextraction solvent for efficient and safe extraction of non-steroidal anti-inflammatory drugs in horse meat.DES was simply synthesized via just mixing choline chloride and phenol at room temperature.The analytes were extracted into acetate buffer,and then back-extracted to the DES phase simply by oscillation.Meanwhile,acetonitrile was used as a dispersive solvent and the DES phase was collected by centrifugation.An ultra high performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) with liquid-liquid microextraction based on the DES was established for the determination of ten non-steroidal anti-inflammatory drugs in horse meat.A series of analytical factors such as extraction agent,dispersing agent and dosage of sodium chloride were optimized.The optimum conditions were as follows:DES was prepared with choline chloride and phenol at a 1∶2 molar ratio,while the horse meat sample was extracted with 5 mL 20 mmol/L acetate buffer(adjusting to pH 3.5 with acetic acid) containing 10 mmol/L ascorbic acid,and subsequently added 1.0 g sodium chloride,0.8 mL extractant and 0.8 mL dispersant,then vortex extracted for 1 min and followed by a centrifugation,finally detected by UPLC-MS/MS.Results showed that there existed good linear relationships for ten non-steroidal anti-inflammatory drugs in the respective concentration ranges with their correlation coefficients(r2) larger than 0.996.The limits of detection(LOD) and the limits of quantitation(LOQ) were in the ranges of 0.05-2.0 μg/kg and 0.10-5.0 μg/kg,respectively.Recoveries for ten non-steroidal anti-inflammatory drugs at three spiked levels ranged from 73.5% to 94.6% with relative standard deviations of 1.1%-8.1%．Results indicated that the DES could be used as an alternate of traditional solvents for dispersive liquid-liquid microextraction.The method was simple,rapid,accurate and reliable,and could be used for the analysis of non-steroidal anti-inflammatory drugs in horse meat．