Abstract: The characteristics of a multi-core cable above a perfect ground coupling to non-nuclear EMP are studied through numerical simulations and experimental investigation, which can be benefit to research the cables coupling effects in command structure. The results of numerical simulations and experimental investigation indicate that a multi-core cable above a perfect ground can couple with narrow band and ultra-wide band HPM. Each core can couple with other cores and the coupling effects are decided by treating methods of the cable’s joints, length and type of cables, angle between cable and incoming wave（direction of polarization）,shielding layer grouding, microwave frequency and so on. The results of numerical simulations and experimental investigation are uniform in regularity, which proves the correctness and feasibility of mathematic mode and experimental method.