Abstract: To study conveniently the electromagretic coupling of Primary Test Stand (PTS) with Z pinch load, based on experimental electrical data analysis and full circuit simulations, a simple lumped circuit model (LCM-PTS) was established and the lumped parameters were discussed in detail. The equivalent voltage was obtained by constructing the open circuit voltage at the tri-plate output water transmission line, which could be fitted by a function of 3.3sin2(t/205). The space electrons current loss in the magnetically insulated transmission line was simplified by flow impedance model. Simulations were carried out by coupling the LCM-PTS model with a 0-dimensional dynamic model of Z pinch loads, and the load currents agreed well with the experimental results.