Abstract: A new lightning protection device using electromagnetic suppression has been developed to enhance the lightning resistance of overhead transmission lines and overcome the limitations of traditional lightning protection devices in reducing the amplitude of lightning current.This method can effectively reduce both the steepness of the lightning current waveform and the peak of the earthward current.The design of the new device′s structure and electrical characteristics are investigated, including the current-carrying coil and the device′s manufacturing techniques.Finally, a prototype is made and subjected to simulation testing.The results indicate that, in comparison to traditional lightning protection devices, the novel device achieves a 54% reduction in the steepness of the lightning current waveform and a 26% reduction in the peak earthward current.Besides, it can accommodate various installation dimensions and directions for tower angle steel, significantly reducing the probability of lightning side flashes and backflashes affecting overhead transmission lines.