The invention belongs to the technical field of grain production equipment, and particularly relates to a grain discharging control system. The grain discharging control system comprises an annular chassis, a C-shaped rotating disc is arranged on the chassis, a plurality of control valves uniformly distributed along the periphery of the rotating disc are arranged on the outer side of the rotatingdisc, each control valve is provided with a discharge port penetrating through a corresponding valve body, turning plates capable of controlling discharge of grain are arranged on the discharge portsin a penetrating mode, the upper ends of the turning plates are positioned above the discharge ports and hinged on the corresponding valve bodies, the lower ends of the turning plates extend to be under the discharge ports and are connected with corresponding the control valves through reset assemblies, shifting rods are arranged on the control valves in a penetrating mode, a C-shaped drive platefixed on the rotating disc is arranged between the rotating disc and the plurality of control valves, a plurality of shifting rod clamping grooves evenly distributed in the circumferential direction are arranged on the periphery of the drive plate, the outer ends of the shifting rods are arranged in the shifting rod clamping grooves, and the shifting rods and the shifting rod clamping grooves arein one-to-one correspondence. Compared with the prior art, the grain discharging control system has the advantages of reasonable design and convenient discharging control.