Abstract: Transmission lines (TLs), which function as the important channel for transmitting signal and energy, are commonly employed in various electronic and electrical equipment. In the meantime, transmission lines are also one of the objects which are susceptible to interference of external electromagnetic pulses (EMPs). Therefore, the coupling problem between the EMP and TLs attracts a persistent attention. In this paper, the classic TL model for analyzing the field-to-line coupling problem at low frequencies, as well as the historical development of both the BLT equation and SPICE equivalent circuit model based on the TL model is introduced and summarized in detail. Meanwhile, the evolution of the FDTD method to solve the TL equation is reviewed. Then, the commonly used field-line coupling models at high frequencies are briefly introduced. Furthermore, some hot issues which are widely concerned in the study of field-line coupling problem are analyzed and discussed, and some areas for improvement are pointed out.