[目的]研究乳粉溶解度的不确定度评定。[方法]根据《GB 5413.29—2010 食品安全国家标准婴幼儿食品和乳品溶解性的测定》中的第二法溶解度的测定来测定乳粉的溶解度。通过分析不确定度的来源,建立完整的数学模型,对模型中的各影响因素的不确定度进行评定和计算,合成相对标准不确定度,计算相对扩展不确定度。[结果]当取置信度为95%时,得到的乳粉溶解度：X=（99.97±1.60） g/100 g,取k=2,扩展不确定度为U=1.60 g/100 g。[结论]该方法可以为乳粉溶解度的不确定度评定提供参考依据。

[Objective]To study the uncertainty evaluation of milk powder solubility. [Method]The determination was conducted according to GB 5413.29-2010.A mathematical model for measurement was set up,and the uncertainty components were analyzed. The uncertainty of each influencing factor in the model is evaluated and calculated,the relative standard uncertainty is synthesized,and the relative expanded uncertainty is calculated. [Result]The confidence probability is 95%,the solubility of milk powder is X=（99.97±1.60）g/100g,k=2,the extended uncertainty evaluation of solubility of milk powder is U=1.60 g/100g （k=2）. [Conclusion]It can be provided reference for uncertainty evaluation of milk powder solubility.