To deal with the problem of aerodynamic and stealth integrated optimization of flywing UAV,A multi-objective optimization study on aerodynamic and stealth of the flywing UAV is carried out which based on the deformation of surface. The FFD parametric method is used to parameterize the wing surface; CFD calculation based on RANS equations is used to analyze the aerodynamic performance of the flywing UAV, large element physical optical method and uniform theory of diffraction are used to calculate RCS of the flywing UAV; And ASMOPSO algorithm with the Kriging surrogate model which based on the expect hyper-volume improvement infill criterion is adopted for integrated optimization design. The results of flywing UAV aerodynamic and stealth integrated optimization exhibit considerable improvement.