Abstract: Wind tunnel model free-flight test is a special wind tunnel test technique between ordinary wind tunnel test and flight test. In this paper, the development of high-speed wind tunnel model free-flight test technology is introduced. Firstly, the development of high-speed wind tunnel model free flight test technology is introduced.Secondly, the common characteristics of wind tunnel model free flight test technology and its three sub-technology——general model free-flight test, multi-bodies separation wind tunnel free-flight test and high speed wind tunnel drop-model test——the difference between the three sub-technologies and their respective application fields are summarized. The common characteristics are support interference-free aerodynamic data and the model free flighting, so that the transient aerodynamic force can be measured at the moment of separation. The repeatability of the test is a common disadvantage compared with the general wind tunnel test. For the three sub-techniques, each has its own characterisitc, and has specific technology and application field from others. The research fields of the three sub-techniques cover the dynamic stability and all kinds of multi-bodies separation of aircrafts. The general wind tunnel free-flight test is applied for the research of aircraft dynamic stability, and the other two sub-techniques are applied in the research of all kinds of multi-bodies separation. While the different multi-bodies separation problems are covered, by the multi-bodies separation wind tunnel free-flight test and high speed wind tunnel drop-model test technique, because of the difference between the specific technology of the two sub-techniques.