Hybrid concepts had been validated in the field of compulsator through the research of several hybrid excitation prototypes. Although there are some advantages for the hybrid excitation compulsator in comparison with the traditional electrical excitation topology compulsator, there still exist some ris ks which may demagnetize the permanent magnets and therefore affect the whole performance and safety operation for the hybrid excitation compulsator. It is necessary to evaluate the demagnetization risks, take some measures and refine the design parameters for the practical application. A very critical problem which exists in the hybrid excitation compulsator is the risk evaluation of demagnetization for permanent magnets during discharge. There are many demagnetization factors for permanent magnets in the hybrid excitation compulsator. The demagnetization magnetic strength, temperature rise and stress effects were analyzed in the paper by the multi-field FEA co-simulation. The temperature distribution in the compensation shield caused by eddy current loss was simulated which is an important temperature rise source for the permanent magnets during discharge. The impact stress imposed on the permanent magnets was simulated and the safety characteristic was evaluated.