The invention provides a special tool for replacing a contact-finger spring of an isolating switch. The special tool comprises a bracket, clamping blocks, a first extruding component, a second extruding component and a down-pressing component, wherein the bracket comprises an installation plate, four skirt plates, four supporting legs and four supporting and stabilizing plates; the two clamping blocks are fixed on the installing plate; the first extruding component comprises a screw fixing frame, nuts, a hand-cranking screw rod and a clamping piece; the structure of the second extruding component is the same as that of the first extruding component; the first extruding component and the second extruding component are respectively arranged at the left side and the right side of the middle-front part of the bracket 1; and the down-pressing component comprises a left supporting plate, a left blocking plate, a right supporting plate, a right blocking plate, a crossbeam plate, a vertical plate, a third nut and a third hand-cranking screw rod. The special tool provided by the invention has the advantages that the structure is simple, and the cost is low; in use, the operating efficiency can be improved, the labor can be saved and the safety of persons and equipment can be guaranteed.