In order to investigate the response characteristics of composites under strong electromagnetic pulse, Ag nanowires (AgNWs) with high aspect ratio were synthesized using polyol method. AgNWs/polyvinyl alcohol (PVA) composite samples with different volume fractions were prepared using PVA as the matrix. The nonlinear conductive behaviors and electromagnetic pulse response characteristics of AgNWs/PVA composites were tested using a power device analyzer and a dynamic response testing system, respectively. The results show that AgNWs/PVA composites within a certain concentration range have excellent nonlinear conductivity characteristics. At the threshold voltage, the conductivity of AgNWs/PVA composites increases rapidly, and the current has a large jump of about 4 orders of magnitude. The nonlinear coefficient α of AgNWs/PVA composite with 1.05vol% volume fraction of AgNWs can be up to 1 959.89. In the vicinity of the square pulse threshold voltage of AgNWs/PVA compo-sites, the voltage amplitude of the output waveform attenuates effectively, which reveals that the conductivity of the AgNWs/PVA composites increases sharply under strong electromagnetic pulse. The AgNWs/PVA composites have the low-pass characteristics of electromagnetic energy, and have a broad application prospect in the field of strong electromagnetic pulse protection of electronic equipment with the function of sending and receiving information.