Abstract: For the study of resistance to electromagnetic interference, the sweep wave irradiation test of a certain type of FM fuse was carried out, which obtained electromagnetic irradiation effects , energy coupling channel and failure mechanisms of the fuze under working. Experiments show that when the projectile axis parallel to the direction of propagation of the radiation field, irradiation energy needed to make fuze malfunction is smallest; With the offset between sweep frequency and operating band of the fuze increased,irradiation energy needed to make fuze malfunchion increase. Refit the fuse and make comparative experiments, we found that fuse antenna is the main coupling path of interference energy. Interference energy coupling by the antenna makes high-frequency circuits disordered, work status of fuses changed, and eventually led to fuze malfunction.