Abstract: Disclosed are a wing and a method for improving a control efficiency of a two-dimensional (2D) airfoil rudder surface. A technical solution is realized by changing an original symmetric airfoil rudder surface into an asymmetric airfoil rudder surface, mounting the asymmetric airfoil rudder surface and a main wing in a misaligned manner to form a gap, and utilizing a gap effect to interfere with a flow on an upper wing surface of the rudder surface, allowing the rudder surface to generate a larger moment, thereby improving a control efficiency of a 2D airfoil rudder surface. According to the present disclosure, a rudder surface control efficiency is greatly improved by simple structural optimization; a pilot is easy to perform operations in a control process; and a control device can utilize an airplane's own components, without introducing large power energy and other driving equipment, no additional load on the airplane.