The high-voltage switchgear shall break the fault current in case of grid fault; During normal operation, load current shall also be switched on and off, and there must be obvious breaking points, and separable contacts shall be equipped. In addition, in order to facilitate assembly and docking. The high-voltage switchgear will also be provided with butt contacts at appropriate positions; A sliding contact is also arranged between the moving part and the stationary part of the conductive body. There is contact surface resistance for both separable contact, butt contact and sliding contact. The size and stability of the contact resistance have a significant impact on the temperature rise of the switchgear during long-term operation and the dynamic thermal stability under the impact of fault current. There are many factors that determine the contact resistance, such as contact surface condition, contact pressure, material hardness and material resistivity. Throughout many factors, contact pressure is an important factor that has a wide range of changes and can be predicted by designers.