Abstract: A pulse forming module combining the function of energy storage and pulse shaping is designed to meet the challenge of minimization and modularization in high-power pulsed power system.The size and weight of the module have been reduced considerably due to the further development of the branches of pulse forming network to the lowest 2, while quasi-square output waveform characteristic is reserved.The module is constructed with a dozen folded film capacitors in series in a solid filmliquid transformer oil insulation system, aiming to prompt its energy storage density and thus the compact and high-voltage design.Influence of the circuit parameters on the output waveform characteristics of the module is studied by using PSpice electrical circuit simulation, and experimental test was carried out to verify it.The module shows high withstanding voltage of 120 kV with stored energy density of 41 kJ·m^-3, and could output a 180 ns quasi-squared high voltage pulse.