Spraying tool for highway construction

The utility model relates to the technical field of construction auxiliary devices, in particular to a spraying tool for expressway construction, which comprises a bottom plate, a water tank and a rain storage tank, the rain storage tank is L-shaped, the water tank is fixed on the lower top surface of the rain storage tank, a mounting tank is fixed at the top of the water tank, a water pumping pipe is arranged in the mounting tank, and the top of the water pumping pipe penetrates through the mounting tank to be connected with a water pump. The top of the water suction pump is connected with the spraying head, the bottom of the water suction pipe is divided into two sections which are arranged in the water tank and the rain storage tank respectively, the floating plate is arranged at the bottom of the rain storage tank, and the blocking rod is fixed to the top of the floating plate. The floating plate in the rain storage tank ascends under the buoyancy action of water, the blocking rod ascends to enter the wat