Abstract: A wind turbine generator system vibration detecting device and method are provided. The device comprises: a plurality of vibration sensors arranged on components of a wind turbine generator systems; at least one vibration switch arranged on a nacelle of the wind turbine generator system to detect a vibration signal of the nacelle and sends a fault signal to a control module if the detected vibration signal is larger than a turn-on threshold of the vibration switch; a vibration estimating module connected with the vibration sensors for processing vibration signals generated by the vibration sensors according to preset weighted values and a weighted formula in order to acquire a vibration state data, and comparing the vibration state data with a preset fault value and sending the fault signal to the control module if the vibration state data is not less than the fault value in accordance with the comparison.