The invention discloses a dust suppression device used in the construction site. The dust suppression device comprises a bottom plate, a casing, a water tank, an atomizing spray pipe, a dust suction cavity and a cylinder, wherein the casing is fixedly mounted at the upper end of the bottom plate, the dust suction cavity is formed in the inner side of the casing, a motor is arranged at the upper end of the dust suction cavity, and the output end of the motor is fixedly connected with a rotating shaft; the cylinder is fixedly mounted at the right end of the dust suction cavity, a piston is glidingly connected into the cylinder, the upper end of the piston is fixedly connected with a threaded rod, and the other end of the threaded rod is connected into a threaded sleeve in a threaded manner;the water tank is arranged on the left side of the dust suction cavity, the lower end of the water tank is fixedly connected with the bottom plate, and a water suction pump is arranged at the upper end of the water tank. According to the dust suppression device, dust suppression treatment is carried out in two modes simultaneously, so that dust suppression efficiency is high, and dust suppressioneffect is good; treated gas is introduced into a hollow cavity of a first rotating rod, the first rotating rod is driven to rotate under the action of arc-shaped spray pipes, therefore, the dust suppression range is enlarged, and energy is sufficiently utilized.