In modern electrical and electronic equipment, the increasing density of components and their related functions restrict the electromagnetic interference. Therefore, the connector is often sealed with a metal shell to prevent internal electromagnetic energy radiation or external electromagnetic interference. At low frequency, only magnetic materials can shield the magnetic field obviously. At this time, the electrical continuity of the metal shell has certain provisions, that is, the shell contact resistance. This is also a part of the current connector market applications, with the increasing demand for high voltage, high voltage screen connection has its mission.