Abstract: In order to study the questions of micro-Doppler effect detection in a laser radar and the extraction of micro-Doppler features indicating target characteristics from radar returned signal,a physical model for micro-Doppler effect in laser radar was built up,then the simulation of the micro-Doppler effect in the laser radar induced by vibration of the target was conducted.Because of the signal is time-varying,joint time-frequency analysis method was introduced.Short time Fourier transform was used to analyze the simulated signal in the time-frequency domain,a micro-Doppler image that can demonstrate the target characteristics was generated.Results show that a laser radar is fit for the detection of low amplitude micro-Doppler effect,and micro-Doppler features can be extracted from radar returned signal effectively by means of timefrequency analysis method.