The invention discloses coherent laser radar for simultaneously detecting atmosphere wind speed and the depolarization ratio. The coherent laser radar mainly comprises a light source emitting module (L), polarization frequency mixing modules (S and P) and a signal processing module 15. Echo signals are divided into S polarization light and P polarization light through polarization beam splitters in the polarization frequency mixing modules (S and P), liner polarization local oscillator light is converted into circular polarization light through a quarter-wave plate, the circular polarization light is divided into S polarization light and P polarization light through the polarization beam splitters, and the S polarization light, the P polarization light and signal light in a corresponding polarization state are subjected to frequency beating. According to the scheme, the utilization rate of the echo signals of the coherent wind measuring laser radar can be increased, and the performance of the coherent wind measuring laser radar can be improved; the signals in different polarization states are measured, the depolarization ratio of aerosol is measured, and detection of the coherent wind measuring laser radar on the condition of the aerosol is achieved.