Abstract: The non-constant voltage charging as pulse transformer to PFN-Marx makes it possible that sections are able to conduct utilizing self-breakdown switches. During charging process, time delay effect brings uneven distribution of the voltage and current on each section, which rises the breaking-down risk of capacities and instability of the system. This article starts form LC ladder and then derives the calculating method of voltage on sections during the process of the pulse transformer charging to PFN-Marx. Furthermore, the influence of parameters in the system and inductors’ arrangement on consistency of the charging voltage is studied. Simulations indicate that method could be a reference when it comes to PFN-Marx designing.