在Ｍｉｅｄｅｍａ二元合金生成热模型基础上，采用规则溶液一级近似理论、自由体积理论以及Ｔｏｏｐ几何模型，建立了三元系中组元活度相互作用系数的计算模型。计算结果与实验值对比效果良好。 Based on the Miedema binary alloy thermal model, the first order approximation theory, the free volume theory and the Toop geometric model are used to establish the calculation model for the interaction coefficients of the components in the ternary system. The calculated results are in good agreement with the experimental ones.