The invention discloses a sand screening device for bridge construction, and relates to the technical field of construction machinery. The sand screening device comprises a screening box, wherein a horizontal frame is arranged in the screening box, a conveying belt is rotationally arranged on the horizontal frame, a drying mechanism which vertically corresponds to the conveying belt is fixed at the inner top of the screening box, a servo motor II is fixedly arranged outside the screening box, and an excitation mechanism which is in transmission connection with a sieve plate is connected with the servo motor II in a driven mode. According to the sand screening device, before sand is screened, a sand fetching tank is driven by the conveying belt to repeatedly turn over the sand, so that the sand is more dispersed; meanwhile, an air injection disc in the drying mechanism is used for carrying out hot air drying on the sand dispersed on the conveying belt, so that the volatilization of water is promoted, the fluidity and the dispersion degree of the sand are higher, the screening efficiency is obviously improved, the excitation mechanism can achieve the up-and-down vibration effect of the sieve plate, it is guaranteed that the fine sand can be accelerated to pass through the sieve plate, and sand screening is more sufficient.