To investigate the electromagnetic leakage caused by braided shielding cable, the finite-difference formulation of braided shielding cable for both the inner shield-conductor circuit and outer shield-ground circuit are proposed. Then, the current in shield-ground circuit induced by the transmitting signal in the cable is computed in time-domain, and the shielding effectiveness of braided shield against trapezoid signals is studied. Further more, the video EM leakage in far zone is calculated. At last, the information leakage caused by EM radiation of braided cable is intercepted and recovered using the simulation platform. It is proved that EM radiation of braided cable can give rise to information leakage. It is a key factor that should be concerned in the information secure field.