Abstract: In order to study the influence of component migration on the circulation and heat transfer pinch point of non-azeotropic mixed working fluid, a theoretical model of high temperature electric heat pump was established. Based on the calculation condition of waste heat recovery in a chemical field, four pure working fluid with better performance were selected according to the requirements of circulating working fluid screening. According to the cycling performance characteristics of the working fluid, they were combined into the mixed working fluid in pairs, and the theoretical analysis of these five mixed working fluid was carried out. Two groups of working fluid combination with better cycling performance were screened out, namely R134a+R245fa（0.4/0.6） and R152a+R245fa（0.4/0.6）. In addition, the correlation between the heat transfer pinch point and component migration of the selected two groups of working fluid was calculated, and the nonlinear distribution of enthalpy in the heat exchanger with component migration considered was obtained. And the result was compared with that without component migration consideration so as to provide theoretical basis for the design and operation of evaporator and condenser. The results show that there are heat transfer pinch points at enthalpy 321.35 kJ/kg and 334.76 kJ/kg, and the size and location of the heat transfer pinch points and the maximum heat transfer temperature difference are affected by component migration.