It is very import and severe test to switch the capacitive current for circuit breaker. Flow condition of thegas in arcing extinguishing chamber is little influence on the switching current because the capacitive switching cur-rent is too low

and the switching process can be approximately no-load condition. Therefore

it is of great engineer-ing significance to calculate the dynamic electric field distribution of circuit breakers when switching capacitivesmall current. Combining the construction characteristics of the circuit-breaker

the method has been given that dy-namic electric field of arcing extinguishing chamber

in the switching process the capacitive switching current

issimulated by APDL and GUI. The key technology

including simulation model for dynamic electric field

dynamicdatum model

max values fetch of electric field intensity for key parts

and plotting curve by APDL and GUI

are re-searched. By these key technologies

it can complete dynamic electric field simulation and get the tendency of themax values of electric field intensity for key parts. Finally

there is a typical live tank circuit-breaker

as an exam-ple

by the method

it has completed dynamic electric field simulation and plotted the curve of the changes of elec-tric field intensity for every key parts

and then it can be used to judge if it is requirement of design. This method hashigh efficiency and universal property;it can guide the design for high voltage circuit-breaker

especially for the cir-cuit-breaker which need switch the capacitive switching current.