The invention provides a fast repairing device for cracks in road engineering construction, which relates to the technical field of road engineering, to solve the problem that when the existing crack repairing devices are in use, the repairing agent is directly poured into the material, and there is a narrow space in the cracks, which causes problems. The repair agent is difficult to reach, so that there are still hidden dangers in the crack, and the way to expand the crack is usually a linear damage repair method, which makes the crack expand and increases the problem of the damaged surface of the crack, including repairing the main body of the car; the owner of the repair car The middle part of the upper end of the body cavity is horizontally slidably equipped with a vertical lifting mechanism. In the present invention, since the middle part of the rotating base at the upper end of the cleaning mechanism is fixedly installed with an inverted servo motor, the repairing mechanism is then slid and clamped in the groove of the guide rail. When the servo motor rotates, the crack can be corrected by the crushing knife, and The gravel can be cleaned through the cleaning head, so that the subsequent repair mechanism can repair it, so that the whole process is consistent.