The residue of antithyroid drug - methimazole in animal-derived food products was studied. The complex matrix of food products was purified by using Cleanert S C₁₈ solid-phase extraction column and the experimental parameters including the loading solvent, washing solution and the eluent were optimized in detail. The method for the accurate and sensitive detection of trace methimazole in pig kidney, liver and muscle samples was successfully developed by combining solid-phase extraction with high performance liquid chromatography. Under the optimized experimental conditions, good recoveries (>85%) were obtained at three spiked concentrations in chosen animal-derived samples with RSD less than 5% (n=3). The limit of detection (S/N=3) and limit of quantitation (S/N=10) achieved to 0.59 μg/kg and 1.97 μg/kg (kidney), 0.54 μg/kg and 1.8 μg/kg (liver), 0.49 μg/kg and 1.63 μg/kg (muscle), respectively, which validated that the developed method with high accuracy and sensitivity could meet the requirement of methimazole detection in real samples.