In order to solve the problem of monitoring and identification of foreign objects in aeroengines. The foreign object impact simulation test was carried out by the fan blade foreign object impact simulation test platform. The Strain Gauging method was used to measure the surface stress of the blade in real time, and the stress analysis method based on the continuous wavelet transform method was proposed to realize the monitoring and identification of the fan foreign object impact event. The test and analysis results show that the dynamic stress amplitude of the fan rotor blade is greatly increased by the impact of the foreign object. The time–frequency analysis method of blade surface stress based on continuous wavelet transform can accurately identify the foreign object impact events of fan blades, including the time, frequency and location of foreign object impact events.