The invention discloses an isolator for a short circuit port of a switch type electrolytic bath bus bar. The insulator has a bilayer structure provided with a switch. The isolator comprises conductive plates, an isolating support, an opening/closing switch and a driving mechanism, wherein the conductive plates are positioned on an end face of the isolator and are respectively connected with two bus bar metal surfaces of the short circuit port; the isolating support is positioned on the inside and an edge of the isolator for supporting two conductive plates and isolating the conductive plates;the opening/closing switch is positioned inside the isolator and is a switch array; a fixed contact of the opening/closing switch is connected with the conductive plates, and a movable contact is connected with the driving mechanism; and the switching on/off of the short circuit port of the electrolytic bath bus bar is controlled by controlling the switching on/off of the opening/closing switch. The isolator can switch on/off the short circuit port under the condition that the short circuit port is closed, control a single electrolytic bath to join and leave the bus bar, and is simple in operation and convenient.