Abstract: A knife switch includes a switch housing, a conductive seat, a movable contact part, and a fixed contact part. The conductive seat, the movable contact part and the fixed contact part are disposed in the switch housing. One end of the movable contact part is electrically connected to the conductive seat. Another end of the movable contact part is formed with a conductive head. An outer surface of the conductive head is defined as a first conductive surface. An arc guide hole having a second conductive surface is disposed in the conductive head. The fixed contact part is provided with a contact finger to cooperate with the first conductive surface and an arc guide contact plate to cooperate with the second conductive surface. The knife switch can ensure the normal use of the main current path when the movable contact part and the fixed contact part are electrically connected.