General high-speed brushless motor is the motor which speed can up to 20,000 rev / min or more. There are main two categories high-speed brushless motor-asynchronous AC motors and DC motors Air circulation mechanism for driving Air circulation mechanism. High-speed brushless motor have such characteristics of high speed, small size, high power density , low moment of inertia , fast dynamic response. It is have greater demand and application prospects both in the military and civilian. For this reason, since the last century , Britain and other developed countries competing carried out on the application of high-speed motor . Currently , high-speed brushless motor which applied in aircraft environmental control system is still in initial stage , but the application prospects is so wide, no matter in air circulation or evaporation cycle , both have great potential. Moreover it is important engineering significance for improving airborne environmental control system performance.