The invention discloses a quantitative separation device for iron tailing sand raw materials. The quantitative separation device comprises a shell, a separation cavity, a first motor, a driving roller, a first connecting roller, a screening belt, a second connecting roller, a linkage roller, a movable seat, a shell, a first spring, an end cover, a
brake cable, a third connecting roller, a connecting
rope, a groove, a sliding block, a first sliding groove, an input funnel, a second spring, a first valve plate, a
pulley, a connecting block, a second sliding groove, a guide groove and the like. The quantitative separation device has the advantages of being reasonable and simple in structure, low in production cost, convenient to install and complete in function; a stirring device is arranged,a
rotating disc can be driven to rotate through a second motor, and the
rotating disc rotates to drive a movable plate and a stirring rod to move left and right through a fixed shaft and a connectinggroove body to stir the raw materials, so that the screening efficiency is improved; and a
pulley mechanism is composed of the
pulley, the connecting
rope and the like, so that the moving range of the first valve plate is enlarged, and the quantitative control range and the control sensitivity are guaranteed.