The invention discloses a construction sand screening machine facilitating automatic discharging and relates to the technical field of sand screening machines. The construction sand screening machine comprises an outer frame. A first motor is fixedly connected with the bottom of the inner wall of the outer frame. A first belt wheel is fixedly connected with one end of an output shaft of the first motor. A second belt wheel is in transmission connection with the surface of the first belt wheel through a belt. The axis of the second belt wheel is fixedly connected with the bottom of the inner wall of the outer frame through a rotary base. A moving device is fixedly connected with the surface of the second belt wheel. A transverse plate is rotationally connected with the right side of the top of the moving device. The left side of the transverse plate is rotationally connected with the left side of the inner wall of the outer frame. According to the construction sand screening machine facilitating automatic discharging, the purpose of increasing the screening speed is achieved, a screen is driven to vibrate, thus the screening speed is higher, the working efficiency is improved, time waste is reduced, sand does not need to be taken out manually, worker burden is relieved, application by people is facilitated, discharging through a discharging port is facilitated, and large-particles sand can be taken out through a box door conveniently.