The invention relates to municipal engineering, and particularly relates to a riverway diversion plugging device for hydraulic engineering and a using method thereof. A base is arranged on a riverbed,a plurality of supporting seats are arranged on the base, a liftable dam body is mounted through the supporting seats, the dam body ascends and descends, adjustment is carried out according to the water level requirement, so that the water storage amount is controlled, the dam body is supported through a dam body supporting device after being lifted, a gap is formed between the riverbed and the lower end of the dam body, due to the action of the dam body, the water level rises, and the water flow pressure intensity of the lower portion of the dam body is increased, the water flow speed is increased, the good desilting effect can be achieved, the bottom of the dam body and the riverbed are not fixed, taking-out and maintenance are convenient, the dam comprises a supporting pipe, a fillingcore is arranged in the supporting pipe, the difference value between buoyancy and gravity can be controlled by controlling the weight of the filling core, then the stability of the dam body is controlled, a corrosion-resistant layer and a waterproof layer are arranged, the good waterproof and corrosion-resistant effects are achieved, and the service life is long.