Presently

the two main development directions of solid insulated switchgear（SIS） are small-size and large-capacity. However

the miniaturization of SIS has restriction on the distance between the internal bus and the vacuum interrupter（VI）. This will not only affect the electrical insulation and partial discharge characteristics of the SIS

but also will affect the current breaking capacity of the SIS. With the transverse magnetic blowing action generated by pass bus conductor

the vacuum arc in a VI blows to burn the shield side and reduce the VI’s withstand voltage level

which has a serious impact on current breaking capacity. In order to improve the breaking capacity of a miniaturization SIS

the purpose of this paper is to study the transverse magnetic blowing action in a SIS

to calculate the electrodynamic force affected by pass bus conductor

and to simulate the magnetic field distribution between contact gaps generated by pass bus conductor. Lastly

a magnetic shielding solutions for the transverse magnetic blowing action is given

which has passed the test verification. The results showed that a magnetic shield in a vacuum interrupter of SIS is a powerful solution to reduce the arc motion affected by bus conductor electrodynamic force

and then to solve the arc transverse blowing action to contact shield in a high-current vacuum interruption.