Abstract: Left boundary of the flight envelope is mainly determined by high angle of attack aerodynamic characteristics of the aircraft layout. The expansion of the left boundary of flight envelope enhances the aircraft's mobility and agility, but it also greatly challenges flight safety. Over the past decades, with the development of flight research technologies for high angle of attack , fighters continuously broke through the flight regime near and above the stalling angle of attack, which pushed left boundary more, expanded flight envelope, reduced flight restrictions, and squeezed more flight potential. This paper elaborates the development and application of key technologies related to high angle of attack aerodynamics including researches on the flow mechanism, numerical computations, wind tunnel tests, aerodynamic modeling and database construction, and integrated verification of aerodynamics and control laws. Along with the author's engineering practice, a systematic and close-loop aerodynamic design and analysis method for flighters at high angle of attack is proposed, consisting of five major parts including pre-design, data-acquisition, aerodynamic force expression, integrated analysis, and integrated aerodynamics/motion/control test, which would be used as reference for related equipment development.