The Unmanned Aerial Vehicle (UAV) with variable forward-swept wing is a new design concept, which integrates the advanced aerodynamic characteristics of orthogonal wing, delta wing and the forward-swept wing. The best performances under different mission demands can be achieved through changing the wing position among the three said configurations. The design of wing-body revolved mechanism, as a key technique, must be hard enough to suffer the lift and moment during varying wing, moreover, the fuselage can not be overweight. Thus, a mechanism with a annular locking groove is proposed in this paper, the high-pressure oil controlled by electromagnetic valves can drive the wing revolution and disperse the stress concentration on root wing through the two sides of annular locking groove.