The invention relates to a distributed wind speed on-line monitoring method for overhead transmission line corridor. The method uses a distributed optical fiber vibration monitor to monitor the optical signal from an optical fiber channel of a transmission line, and then filters and preprocess the sampled signal for de-noising through a morphological filter to further obtain the vibration frequency and vibration amplitude of the vibration parameters at each particle point of the fiber channel included in the signal at current time. Therefore, the relationship is established between the lifting force, the wind speed and cable vibration parameters on the unit length in the vertical wind direction on the surface of power transmission line to monitor the wind speed.