Abstract: A coherent receiving device and anemometry lidar system. The device includes: a polarization maintaining optical fiber pin for receiving local oscillation light and outputting it to frequency mixer; a polarization beam splitting prism for receiving signal light, splitting it into first and second signal light, and outputting them to the frequency mixer; the frequency mixer for mixing the first and second signal light with the local oscillation light and outputting the mixed light to PD array; the PD array for converting the mixed light to differential current signal; and a signal processing circuit for converting the differential current signal to differential voltage signal whose derivation formula includes part of frequency difference between the signal light and local oscillation light, detecting a frequency of the differential voltage signal to obtain a value of the frequency difference, and obtaining Doppler frequency shift amount of the signal light according to the value.