Abstract: Technical details of using acoustic emission to real time monitor the health status of the main landing gear beam during its fatigue test were introduced. Taking advantage of using trend analysis, amplitude-based analysis, space-based analysis and other methods, it was found that high-amplitude and high-energy signals existing in one area of the landing gear beam. For further verifying whether there is fatigue damage, it was decided to use correlation analysis-based trend analysis to process AE signals again, thus checking up the possibility of fatigue crack. With the help of Fisher linear discriminated method, this paper established a discriminated mode between normal and abnormal signals, providing an important guarantee for fulfillment of the test and also providing a reference for the identification of fatigue damage signals and abnormal signal for the subsequent data processing.