In order to ensure that the capacitor charging power supply of modular pulsed power source to work reliably in intense pulse current environment in pulse forming network（PFN）

it is necessary to analyze the magnetic interference and its suppression methods on the control and detection circuits of capacitor charging power supply. On the basis of the finite element analysis software Ansoft Maxwell

we research the modular pulsed power source

which is integrated by capacitor charging power supply

energy storage capacitor

and pulse forming network by 3D modeling and electromagnetic simulation. The results show that the shielding effectiveness（SE） of enclosure enclosure is better with larger magnetic permeability and electric conductivity. Compared with other shape holes

circular array holes are more suitable for improving SE. Moreover

the SE tends to be stable when the thickness of enclosures approaches surface effect depth. When printed circuit boards（PCBs） are placed parallel with the smoothing inductor

there is the least electromagnetic interference.