The invention discloses a fast disassembling and assembling device for a scissor type disconnecting switch closing pressure spring. A disconnecting switch comprises a moving contact finger; the contact finger comprises a first rod body, a second rod body and a bolt; a pressure spring sleeves outside the first rod body and presses against between the first rod body and the second rod body; the first rod body and the second rod body are axially limited through the bolt; and under the elasticity action of the pressure spring, the bolt is relatively fixed with the two rod bodies. The device comprises a sleeve, a fixing piece and an ejector rod, wherein the contact finger is arranged in the sleeve; the first rod body and the sleeve can be fixed through the fixing piece in an assembling and disassembling way; the ejector rod stretches into the sleeve and presses against the second rod body, and the ejector rod is inwards pressed to drive the second rod body to move inwards, so that the pressure spring is further compressed, and the bolt is free of being acted by the elasticity of the pressure spring; and the bolt is taken out from a disassembling and assembling window, so that the pressure spring can be conveniently disassembled. The whole disassembling process is simple and reliable; and in addition, when the bolt is disassembled, the pressure spring is only reset in the sleeve, sothat operating personnel cannot be hurted.