Study the influence of the deformation of the wing on the aerodynamic characteristics of the small guided bomb. Use bi-directional fluid-solid coupling method to calculate the aerodynamic parameter and deformation of flexible-wing of three-wing configuration guided bomb, and calculate the aerodynamic parameters of rigid wing by FLUENT. The simulation results indicate that the two wings of guided bomb lift coefficient, drag coefficient and lift to drag ratio along with the trend of the angle of attack and the change of speed in the same; guided bombs of the flexible wing lift coefficient and lift drag are larger than that of the rigid wing; drag coefficient of flexible wing is less than rigid wing; the maximum deformation of the flexible wing is linear with the angle of attack. The aerodynamic characteristic of the guided bomb with flexible wing is better than that of the rigid wing.