By analyzing the acoustic emission detection signal of composite winding shell in the process of external load test, this paper gives damage feature signal descriptions and identifies the severely damaged parts according to the location of the acoustic emission sensors and the concentration of damage feature signal. Experiments show that Amplitude>80 dB & Duration<3 ms single is a major cause of composite winding shell in the process of external load test. Finally, general acoustic emission detection approach of composite winding shell is presented.