Scanning electron microscopy (SEM) and energy dispersive X-ray spectrometer (EDS) were used to analyze the microstructure and composition changes in the aging process of Sm2Co17 type permanent magnet. The microstructure changes of such magnets in the aging process with the aging temperature and time changes in the law were revealed, and the typical SEM image of microstructure of normal sample was identified. The result of this method is more accurate and more intuitive than optical microscope, and the sample preparation is easier than that of transmission electron microscopy. The application in the production control effect is remarkable