铁路通信系统中会用到各种信号电缆连接信号设备，而高压直流输电线路在故障状态下和直流侧谐波会对铁路通信线路产生影响。因此，铁路通信线路受到影响的相关研究具有确保铁路运输效率和秩序的现实意义。根据强电线路对弱电线路的电磁感应原理，介绍了高压直流输电线路对铁路通信线路影响的机理及计算方法，并依据我国高压直流输电线路对通信线路影响的限值，对不同参数变化下的感应电动势和杂音电动势变化情况通过PSCAD/EMTDC软件平台进行仿真，得出了这些参数对于感应电动势和杂音电动势的影响程度。最后，提出了防护措施以抑制危险影响和干扰影响。

A variety of signal cables are used in railway communication system to connect signal equipments, while HVDC power transmission lines in fault condition and DC side harmonics exert impact on railway communication lines. So the research on the influence degree of railway communication has practical significance to ensure railway transport efficiency. According to the principle of electromagnetic induction of power lines on weak current circuit, the theory and calculation methods of influence of HVDC power transmission lines on railway communication lines are introduced in this paper. Based on the limit of influence of HVDC transmission lines on communication lines in China, the induced voltage and disturbance voltage are calculated and simulated in PSCAD/EMTDC with the changes of different parameters, in which the influence degree of different parameters on induced voltage and disturbance voltage is obtained. Finally, some protective measures are suggested to restrain dangerous effects and interference effects.