Abstract: The large scale continuous transonic wind tunnel has several main features, such as the large-size test section, high wind tunnel performance specifics, large scale wind tunnel system, multi-function wind tunnel operation. It has the test capabilities of accurate simulation of the aircraft shape, aero-elastic evaluation and integrated body/propulsion design. This paper briefly introduces the overall design of the large continuous transonic wind tunnel, and special focus is put on the preliminary research results of key technologies such as the realization of world-class flow quality and the development of the large axial compressor and its driving system.