The utility model relates to an edge cleaning device for welded junctions of thick plate components. The edge cleaning device comprises a flat plate, a support frame is arranged on the left side of the flat plate, a first rotating shaft is mounted on the support frame through a bearing cap, a first cleaning wheel is mounted on the left side of the first rotating shaft, a first motor is mounted on the right side of the first rotating shaft, a vertical plate is mounted on the left side of the support frame, connecting and pressing plates are hinged to the upper end and the lower end of the vertical plate, a second rotating shaft is arranged on each connecting and pressing plate, a second motor is mounted on each of the upper and lower portions of each second rotating shaft, a second cleaning wheel is mounted at the other end of each second rotating shaft, bent compression springs butting against the connecting and pressing plates are mounted on the right sides of the upper and lower ends of the vertical plate through bolts respectively, a tension spring is arranged between the left side of each of the upper and lower ends of the vertical plate and each connecting and pressing plate, and grinding wheels or steel brushes are arranged on the first cleaning wheel and the second cleaning wheels respectively during operation. Being of the structure, the edge cleaning device is simple in structure, convenient to operate, wide in application range and clean in cleaning.