Granulation structure for agricultural fertilizer production machine

The grain selecting structure for the agricultural fertilizer production machine comprises a coarse screen frame and a screening mechanism, connecting legs are welded to the outer side of the coarse screen frame, and a discharging opening is welded to the top end of the coarse screen frame. The screening mechanism comprises a screening plate, a vibration motor, a spring, a first rotating steering engine, a rotating clamping seat, a moving pile, a lead screw, a connecting bearing, a coupler, a servo motor, a lifting pile, a second rotating steering engine, a bearing plate and an auxiliary pad, the screening plate is arranged at the bottom end of the discharging opening, the vibration motor is connected to the top end of the screening plate through screws, and the spring is welded to the bottom end of the screening plate. A servo motor is controlled to work through a control seat, a lead screw is driven to rotate through a coupler, a movable pile moves on the lead screw, the height of a screen is reduced, then