为了研究近地面电缆屏蔽层对高空电磁脉冲的耦合规律,依据传输线理论,计算了在高空核电磁脉冲作用下损耗大地上电缆屏蔽层上的感应电流。利用快速傅立叶变换技术,首先得到近地面电缆屏蔽层感应电流的频域解,然后采用快速傅立叶逆变换技术得到时域解。得到了感应电流随电缆长度、电缆架设高度、电磁脉冲极化角、方位角、俯仰角、端接阻抗和大地电导率等的变化规律。“,”In order to research the response of cable sheath near ground to HEMP,the induced currents in cable＇ s shield are calculated based on transmission line theory.By using fast Fourier transform technique,the currents in frequency domain are obtained,then using fast Fourier inverse transform technique the currents in time domain are obtained.The patterns of induced currents with the parameters of the cable＇ s length,height,polarization angle of electromagnetic pulse,orientation angle of electromagnetic pulse,pitching angle of electromagnetic pulse,resistance and earth conductivity are obtained.