Objective: An ultra-high performance liquid chromatography-tandem mass spectrometry method was established for the simultaneous determination of 27 antiparasitic drug residues in Litopenaeus vannamei. Methods: The solution was used to extract antiparasitic drugs in the samples of L. vannamei. The supernatant after centrifugation was purified by C₁₈ and neutral alumina powder. The sample solution was analyzed by ultra-high performance liquid chromatography-tandem mass spectrometry and applied to the instrument workstation to perform data analysis. A Thermo Hypersil Gold aQ column was used as the separation column, and 0.1% formic acid acetonitrile and 10 mmol/L ammonium formate solution （containing 0.1% formic acid） were invoked as the organic phase and the aqueous phase for gradient elution, respectively. The electrospray ion source was used for positive and negative ion synchronous scanning and multiple reaction monitoring modes. The ion abundance ratio was qualitative, and the matrix-matched reference solution external standard method was employed for quantitative analysis. The results showed that the Pearson correlation coefficient （r） of 27 antiparasitic drugs was greater than 0.974 1 in a certain concentration range, and the linear relationship was good. Results: The detection limit was 0.5～2.0 μg/kg, and the quantification limit was 2～5 μg/kg; The recoveries （n=6） of the method spiked at the low, medium and high concentration levels of the samples were 61.90%～118.54%, the intra-assay coefficient of variation （n=6） was 0.57%～12.56%, and the inter-assay coefficient of variation （n=3） was 1.29%～16.47%. Conclusion: The method has good selectivity, high method recovery rate, high precision, and short measurement period, provides a robust and efficient method for the determination of antiparasitic drugs in the laboratory, and meets the testing needs of the laboratory.