Abstract: A kind of external wing structure able to improve the acoustic stealth performance is proposed based on the Fresnel half-wave zone theory for increasing acoustic stealth demand of small underwater vehicles. The improvement effect of acoustic stealth performance of the optimized airfoil structure with different structural parameters is analyzed by plate element method. The research shows that the wing blocks the half-wave zone with the largest contribution of cylindrical scattering, which leads to the acceleration of phase change and the reduction of the scattering contribution of the same projected area in the incident direction. The target strength in abeam direction of the cylinder can be effectively reduced. When the opening angle of the wing covers the first Fresnel half-wave zone and the wing is tangent to the cylindrical body, this structure can improve the acoustic stealth performance best while saving the manufacturing costs. Acoustic scattering experiment of the winged cylindrical model is conducted in the pool. The target strength of the optimized structure in the 0 degree direction decreases about 7 dB, and the angle detection probability in the pitch direction after optimization is greatly reduced. Hence, this type of winged structure is beneficial to improving the acoustic stealth performance.