A scraper comprises a host, a quick changing device, a working device and a hydraulic system; the quick changing device comprises a base frame and an ear plate, a locking hydraulic cylinder is fixed at the lower part of the front side of the base frame, and an upper lockhole plate with a lockhole is fixed on the base frame and positioned under the locking hydraulic cylinder; the working device comprises an executive component at the front part and a bracket at the rear part; an lower lockhole plate with the lockhole is fixed at the lower part of the rear side of the bracket, and a positioningblock is arranged on the bracket and positioned above the lower lockhole plate; the quick changing device is connected on a first rocker of the host and a pair of movable arms respectively by the base frame and a pin shaft, the working device is hung on the tops taking the shape of furcation of the two ear plates of the quick changing device by two first pin shafts on the bracket, and a piston rod of the locking hydraulic cylinder is inserted into the lockhole of the upper lockhole plate of the quick changing device and the lockhole of the lower lockhole plate of the working device so as to lock the working device and the quick changing device. The scraper adopts hook type connection and the locking mode of the lock shaft, and has simple structure, correct and firm connection, and quick change of the working device.