Building facade dismantling device and dismantling method

The building facade dismantling device comprises a cutting mechanism, a shoveling mechanism and a power mechanism, the cutting mechanism comprises two tool bits which are symmetrically arranged, the tool bits are connected with a water source through water pipes, and the shoveling mechanism comprises a scraper knife arranged between the two tool bits; the power mechanism comprises a box body, a compression system and a driving system, the compression system and the driving system are arranged in the box body, the compression system is used for pressurizing a water source, and a vibrating spring is connected between the scraper knife and the driving system; wherein the tool bit and the scraper knife are located on the same plane to form a dismantling plane, the driving system is connected with the scraper knife and drives the scraper knife to reciprocate along the dismantling plane, the dismantling plane is parallel to the building facade, and the scraper knife is attached to a facing layer of the scraper knif