为了分析和评估液相色谱-串联质谱法测定葡萄中噁唑菌酮农药残留量时的不确定度，以《植物源性食品中331种农药及其代谢物残留量的测定 液相色谱-质谱联用法》（GB 23200.121-2021）及《水果和蔬菜中450种农药及相关化学品残留量的测定 液相色谱-串联质谱法》（GB/T 20769-2008）标准方法为研究对象，选择农药噁唑菌酮，针对样品称量、前处理溶剂体积、制备标准溶液及工作曲线拟合等六个方面对方法的测量不确定度进行了评估。结果表明，噁唑菌酮农药残留的相对扩展不确定度约为0.22%（k=2），其中主要的不确定度来源于液质联用仪的使用、标准溶液的配制、标准曲线拟合以及加标回收率等方面。为了降低检测结果的不确定度，在实际工作中，我们需要从提升设备稳定性、优化标准溶液的配制流程以及提高检测人员的操作技能等方面入手进行改进。同时，我们也应将不确定度的结果作为重要参考，用于判断限量临界值数据是否符合限量标准要求。

In order to analyze and evaluate the uncertainty of determination of famoxadone pesticide residues in grape by UPLC-tandem mass spectrometry, the pesticide famoxadone was selected to evaluate the measurement uncertainty of the methods from six aspects including sample weigh, standard solution preparation and standard curve fitting, etc., with "National food safety standard-Determination of 331 pesticides and metabolites residues in foods of plant origin-Liquid chromatography-tandem mass sprctrometry method" (GB 23200.121-2021) and "Determination of 450 pesticides and related chemicals residues in fruits and vegetables-LC-MS-MS method" (GB/T 20769-2008) standard methods as the research objects. The results showed that the relative extended uncertainty of famoxadone pesticide residue was about 0.22% (k=2), in which the main uncertainties were derived from the use of UPLC-tandem mass spectrometer, standard solution preparation, standard curve fitting and standard recovery rate. In order to reduce the uncertainty of test results, in actual work, we need to improve the stability of equipment, optimize the preparation process of standard solution and improve the operating skills of test personnel. At the same time, we should also take the results of uncertainty as an important reference to judge whether the limit threshold data meets the requirements of the limit standard.