The invention relates to a temperature rise analytical method for predicting temperature of a permanent magnet in a permanent magnet synchronous motor (PMSM), belonging to the application electrical engineering design field; the method is characterized in that: distributed heat source of a motor is analyzed by a filed-circuit compact coupling method, comprising eddy current loss in the permanent magnet, iron loss in an iron core and copper loss in armature; on the consideration of precision requirements, the coupling analysis of a magnetic field and a temperature filed can be realized by single-way coupling mode. A thermal model of the permanent magnet synchronous motor is built based on a mixing method of a novel equivalent heat network and a finite element, heat parameters are rationally selected by adopting a combining mode of experimental measurement and empirical formula, the heat transferring coefficient and cooling condition of the motor are described completely, a stator and a rotor can be systematically combined by adopting air gap joints in the heat network, the stator and rotor unified temperature rise model is formed, the difficulty of measuring air gap temperature is avoided, material parameters are adopted at the practical working temperature, so as to lead the analysis to be rational; the accurate and optical method for predicting the temperature of the permanent magnet is realized by special correction processing in experimental links; in addition, the design method is used to give suggestions for model selection of the permanent magnet material in the motor.