Isolation switch is a switching device mainly used for isolating power supply, switching operation, connecting and cutting off small current circuits, without arc extinguishing function. When the isolation switch is in the open position, there is an insulation distance between the contacts that meets the specified requirements and obvious disconnection marks; When in the closed position, a switchgear capable of carrying the current under normal circuit conditions and the current under abnormal conditions (such as short circuits) within a specified time. Generally used as a high-voltage isolation switch, that is, an isolation switch with a rated voltage above 1kV. Its working principle and structure are relatively simple, but due to its large usage and high reliability requirements, it has a significant impact on the design, establishment, and safe operation of substations and power plants. The main characteristic of the isolation switch is that it has no arc extinguishing ability and can only open and close the circuit without load current. The entry introduces the functions, characteristics, types, applications, error prevention improvements, maintenance, common problems, etc. of isolation switches