The invention relates to a disassembling and assembling device of a corner clamping plate positioning and tensioning device. The disassembling and assembling device comprises a fixed base, a movable base, a driving part, a fixed arm, a movable arm and a handle, wherein the movable base is arranged below the fixed base, the driving part is installed on the fixed base and is used for connecting anddriving the movable base to move up and down, the fixed arm is arranged on the side surface of the fixed base and is unfolded outwards, and the movable arm is arranged on the movable base and is unfolded outwards; and the handle is L-shaped, the middle bent position of the handle is hinged to the end, which is outwards unfolded, of the fixed arm, one end of the handle is movably connected to the end part, which is outwards unfolded, of the movable arm, and the other end of the handle is bent downwards. Compared with the prior art, the disassembling and assembling device can replace manual assembling and disassembling of the positioning and tensioning device, the labor is liberated, the production rate is improved, and the bonding quality of a corner clamping plate is improved.