Abstract: Considering operation features of magnetically insulated transmission line(MITL), the circuit simulation method of MITL is explained, and the MITL circuit simulation code based on wave process is developed. The physical descriptions of the criterion of MITL operation status, operation impedance and loss current are discussed. The effects on simulation results due to different physical models are analyzed. The analysis indicates that loss resistance due to overmatched impedance has significant influences on MITL circuit simulation. The circuit simulation based on existing physical model is posterior, and it is useful in wire arrays configuration design, load current and implosion characteristic estimation. The MITL design, especially for future higher current MITLs, needs deep insight into magnetic insulation phenomena and operation processes.