Excavation method for reserved protective layer of disintegrating rock

An excavation method for a reserved protective layer of disintegrating rock mainly comprises the steps that an unmanned aerial vehicle route is arranged according to control points of a to-be-operated area range, a low-altitude unmanned aerial vehicle is adopted for aerial photography, and an original terrain image is collected; generating point cloud data; marking an area which does not meet the standard requirement, namely a to-be-milled operation area, and obtaining point cloud data of the to-be-milled operation area; superposing the point cloud data of the to-be-milled operation area, an airborne GPS coordinate of the milling machine and a coordinate of a laser guide sensor above a tool bit of the milling machine to the same coordinate system to generate a three-dimensional topographic map with an excavation size; transmitting the three-dimensional topographic map to an airborne display end of the milling machine; and an operator of the milling machine carries out milling operation according to the guidan