This paper establishes a mathematical model of the fridge evaporator reliability life, and then describes a mathematical method determining the main industry quota ( the fridge ecaporator sand hole equal initial depth) on the evaporator manufacturing stuff though the mathematical model. 建立了电冰箱蒸发器可靠性寿命的数学模型,并给出了由数学模型确定制作蒸发器材料主要工业指标(砂眼平均初始深度)的数学方法。