The pulse supply system can instantaneously discharge to a transmitting device through a high-power special coaxial cable. The proximity and skin effect exist on the conductor under the condition of instantaneous pulse high current and the cable impedance characteristics instantaneously change. Consequently

we established a transient circuit model of coaxial cable based on partial element equivalent circuit. The impedance characteristics in time domain and frequency domain of coaxial cable were analyzed

and the current distributions and transient voltage distribution were calculated.Moreover

the frequency domain vector fitting method was used to fit the frequency-domain impedance characteristics of coaxial cables. The Foster equivalent circuit model of the coaxial cable was obtained. The model has the advantages of fewer nodes

fewer branches and higher applicability relative to the partial element equivalent circuit model. Finally

a pulse power discharge test platform was set up to conduct discharge tests at different voltage levels. The transient voltage curves of the coaxial cables were obtained and compared with the simulation results. The experimental results verify the correctness of the theoretical analysis.