The present invention relates to a wind velocity measurement method, a wind velocity estimator and an unmanned aerial vehicle (UAV). The wind velocity measurement method includes: determining current wind resistance interference of a UAV by means of system identification based on flight data and attribute data of the UAV; and calculating a wind velocity of a flight environment of the UAV according to the wind resistance interference and the inherent wind resistance of the UAV. The method realizes the wind velocity measurement by identifying parameters based on the principle of system identification without a newly added wind velocity sensor and an external database. Therefore, not only hardware device costs are saved, but also an additional computing burden and a problem about real-time performance are avoided. The method is simple and requires low costs.