Abstract: Aiming at the failure problems in the actual use of field emission scanning electron microscope, the causes of the failure were analyzed in detail, and the solution to the failure of the scanning electron microscope was given in combination with the actual situation. The results show that the main reason for the two failures was that when the scanning electron microscope was turned off and turned on again, the instantaneous voltage or current of the boot caused some damage to the components on the equipment, which eventually led to the failure of the scanning electron microscope boot. The results could provide strong technical support for the testers.