The invention discloses a grit screening device for constructional engineering. The grit screening device comprises a body and supporting legs arranged at the bottom of the body. A universal wheel ismounted at the bottom of each supporting leg. A screen plate is mounted at the inner top of the body. The top of the left side of the body is provided with a connecting rod. The left side of the connecting rod is connected with an adjusting rod. A motor is mounted on the left side of the bottom of the body. A rotating disc is mounted at the end of a rotating shaft. A fan is mounted at the bottom of the left side of the body. A first discharging opening and a second discharging opening are formed in the bottom of the right side of the body. Collection grooves are correspondingly formed in the bottom of the first discharging opening and the bottom of the second discharging opening and are welded between the supporting legs. According to the grit screening device, centrifugal force improved through the manner that the motor drives the rotating disc to rotate is utilized for throwing out grit, meanwhile, wind power provided by the fan is used for blowing treatment, the grit falls to the first discharging opening under the action of gravity, impurities and turfgrass clippings fall to the second discharging opening, the collection grooves are used for unified collection, and the screening efficiency is high.