Abstract: Aiming at the development requirements of high lift-drag ratio and low thermal load of a new type of high-speed flight vehicle in the future, a large swept delta wing which is close to the practical engineering is chosen as the study object in this paper. Numerical simulations on the effects of large-area wall mass injection on the drag and heat reductions in flight states are carried out, and the influences of mass injection on the aerodynamic force and heat characteristics of delta wing under different flight altitudes, freestream Mach numbers, injection flow rates, injection temperatures and gas models are compared and analyzed. Based on the engineering requirements of drag and heat reductions of high-speed flight vehicles, the issues of wall mass injection in the engineering applications and the research directions that deserve more attention in the future are pointed out.