The invention relates to a quick dismantling method for a safety protective shed of an overpass high-speed railway operation line. Firstly, quick dismantling devices of the safety protective shed of the overpass high-speed railway operation line are manufactured and mounted; when safety protective shed roof panels and longitudinal secondary beams are dismantled, through moving of the quick dismantling devices on the two sides of the protective shed on a railway, components such as the dismantled protective shed roof panels and secondary beams are manually moved to the quick dismantling devicesto be disassembled and outwards transported; and when transverse primary beams are dismantled, through cantilever cranes on the quick dismantling devices, the primary beams are horizontally moved toa reserved operating platform of a nearby station building to be disassembled. According to the quick dismantling method, the problem that the spaces of certain actual construction sites are insufficient and thus the cranes cannot be used is solved, operation is easy, and the construction efficiency is high.