Abstract: FL-7 is a continuous transonic wind tunnel,which is powered by three engines.Mach number is adjusted by the rotating speed of engines,the flexible wall nozzle and the by-pass valve.It is difficult to establish the precise mathematical model,because there are many aspects influencing the Mach number.We use the fuzzy control with function of self-learning for getting better in speed and precision of Mach number control.And then we have got more satisfied results.This paper describes the methods and the rules of control.