In order to effectively calculate the electricity-generating performance parameters of semiconductor thermoelectricgenerator units,the existing calculation model based on constant material properties is analyzed,and anew model based on variable material properties,which includes the procedures of solving the temperature distributionof semiconductor particles and calculating the material parameters as well as the electricity-generating performanceparameters,is proposed.Then,the two models respectively based on constant and variable material propertiesare used to calculate the performance parameters of a semiconductor thermoelectric generator unit in various workingconditions.The results are finally compared with those of ANSYS simulation. It is found that the proposed modelbased on variable material properties is superior to that based on constant material properties because it greatlyreduces the calculation error.