Abstract: To investigate the aerodynamic characteristics of a supercritical airfoil RAE2822 with jet on the lower surface of trailing edge (LSTE jet) in transonic conditions, Reynolds Average Navier-Stokes (RANS) equation and Spalart-Allmaras (SA) turbulence model are adopted for the numerical simulation. The results show that the LSTE jet increases the wave drag and the lift of the airfoil when there is a shock wave on the upper wing. The overall optimization method of the airfoil with LSTE jet is proposed. The optimization method based on Kriging surrogate model is adopted to optimize the shape of RAE2822 airfoil without and with LSTE jet (c_µ=0.0002) to achieve the maximum lift-to-drag ratio. The results show that compared with the baseline airfoil, the equivalent lift-to-drag ratio of the airfoil with LSTE jet is increased by 4.9% and the equivalent lift-to-drag ratio of the optimized airfoil with LSTE jet is increased by 26.2% when Ma=0.73, Re=6.5×10⁶, α=2°. The overall optimization design method of airfoil with LSTE jet can significantly improve the equivalent lift-to-drag ratio of supercritical airfoil, and the research results are helpful to the application of LSTE jet.