The eddy current on the shielding of electromagnetic railgun is induced by the pulse current

which weakens the propulsion of armature and reduce the projectile velocity. Also

the insulating layer will be impaired by current density gathering caused by eddy current. Therefore

it is very important to investigate the eddy current and its loss. Using the 3-D electromagnetic railgun model of finite element

we analyzed the eddy current

and calculated eddy-current loss. Moreover

we discussed the variation characteristics of eddy-current loss

maximum eddy-current density

and the propulsion of armature with the influential factors such as the material

the size of shielding

the amplitude

and the waveform of pulse current. The results show that eddy current will be inhibited and the propulsion of armature will be promoted by using high permeability and low conductivity material for shielding

which is not obvious through increasing the inner diameter of shielding or decreasing its thickness

the harm of eddy current can be reduced with employing low amplitude and wide flat-topped pulse current.