In order to expedite power restoration after cable failures, a plug-in GIS (Gas Insulated Switchgear) intermediate joint is designed for cable quick repair/test. During the electric field simulation of this intermediate joint, significant electric field distortions were observed at the metal stress cones and the cable’s semi-conductive layer discontinuity, indicating potential weak points in insulation. To mitigate the electric field distortions within the joint, investigations were conducted on the impact of factors such as the gap width between the metal stress cones and the XLPE cable, the relative position of the semi-conductive layer discontinuity, the stress cone, and the winding length of high dielectric constant tape. The design and installation scheme of the metal stress cone wasa obtained through simulation, which provides a basis for the design and manufacture of the GIS quick repair/test joint.