The invention relates to a device for receiving welding slags generated during welding reinforcing steel bars to wet seams of a municipal engineering bridge, and an implement method of the device. The device aims to solve the problem that the welding slags and sparks drop out during the welding construction of reinforcing steel bars on the wet seams behind a box beam in engineering such as a municipal engineering viaduct bridge. The device comprises a receiving disk with a rectangular bottom plate. The device is characterized in that the receiving disk is provided with a frame of which the height is smaller than or equal to 30mm, and an operating rod is arranged at an off-centered position in the length direction of the bottom plate of the receiving disk; the operating rod is a U-shaped rod component, and a hook is arranged on one side of the operating rod; a plurality of grooves distributed in the length direction are formed in the bottom of the receiving disk. The device can effectively receive the welding slag and the sparks generated during welding, is simple in structure, easy to manufacture and operate, low in cost and good in practicality, and can be reused.