The invention belongs to the technical field of valves, and discloses a rotary control valve with high flow controllability. The rotary control valve with the high flow controllability comprises a valve body, a valve rod and a valve plate. The valve rod penetrates through the top and bottom of the valve body and is connected with the valve body at the penetrating positions through bearings. The valve body comprises a medium inlet and a medium outlet, and a rubber sealing ring matched with the valve plate is installed in the valve body and located at the medium inlet end. An arc-shaped protrusion is arranged on the surface, facing towards the medium outlet, of the valve plate, the arc-shaped protrusion is arranged close to the periphery of the valve plate, and the convex surface of the arc-shaped protrusion and the rubber sealing ring can be in contact with each other or form a gap of less than 5mm when the valve plate rotates by 0-70 degrees. By arranging the arc-shaped protrusion on the valve plate, the medium resistance is high at the contact point or the gap between the arc-shaped protrusion and the rubber sealing ring, so that flow cannot pass through the contact or the gap, thus, the flow at the medium outlet is limited, and the low opening controllability of the rotary control valve is improved effectively.