Coaxial electrodes structure is applied widely in high power pulse apparatus.Based on ANSYS software package

the influence on coaxial spatial electric potential or electric field strength is calculated as the parameters variation

such as inner electrode diameter

flashover length

and solid dielectric factor

etc.

Through comparing calculating results with simulating results

variable tendency of edge-effect of coaxial electrodes is ascertained.The effective length of the electrode is attained

in which edge-effect of coaxial electrodes doesn’t interfere flashover properties on solid dielectric surface

and reference equations between the least electrode length and inner electrode diameter and flashover length in the some range of inner electrode diameter are pointed out.The simulating results can guide experimental study on flashover properties in coaxial electrodes.