Abstract: The seamless high-lift technology is a rising direction which is adapted for the reason of environmental requirements concern. A clean airfoil based on MD-30P30N multi-element airfoil is built, research on seamless deflection at leading and trailing edge, including parameters of deflection proportions and angles are investigated using the software of FLUENT. Circulation control technique (active trailing jet) is adopted to eliminate the trailing edge flow separation at high angle of attack, and the momentum coefficient and nozzle height are studied at the same time. Using the multi-discipline optimization software of ISIGHT, the multi-parameter optimization is also carried out based on the optimized response surface, in which the Multi-island genetic algorithm is adopted. The results show that, the equivalent high-lift capability could be achieved compared with that of MD-30P30N. The possible value in engineering application of this method is validated.