To research jamming method and effect for radio fuse frequency modulated by triangular wave, the continuous wave of the same center frequency as that of the radio fuse was applied. It was found that when the jamming signal is up to certain energy, it can suppress the true echo signal of the target. Theoretical analysis and computer simulation prove the reason why the phenomenon occurs is that the continuous jamming wave has wide-band after mixing to cover and suppress the spectrum of the true echo signal of the target, but the jamming signal can’t satisfy the judge condition of distance and speed, so the fuse won’t startup wrongly.