Aiming at the centrifugal tensile stress failure of permanent magnets on the rotor for super high-speed air compressor in high-power fuel cell system, the magnitude of interference between the sleeve and the permanent magnet as well as the stress at the rated speed are calculated by the analytical method. Then, a two-dimensional axisymmetric model was established by the finite element method to calculate the stress distribution, and the accuracy of the analytical method and the finite element method was compared. Furthermore, the influence of temperature rise and sleeve material on stress is studied based on the finite element method. The results show that the calculations of the two methods differ no more than 2.5%. Among the influencing factors, both the rotational speed and the temperature rise cause a significant increase in the stress of the permanent magnet, and it is necessary to increase the interference in order to provide protection for the permanent magnet. Additionally, the carbon fiber sleeve can reduce the stress of the permanent magnet by at least 42.1% when compared with the alloy sleeve, and the effect is particularly obvious under high temperature conditions. Therefore, reducing the rotating speed, increasing the assembly interference and improving rotor cooling can effectively optimize the structural strength, and the composite material sleeve is more suitable for protecting permanent magnets than the steel sleeve.