Blade running state monitoring system for offshore wind turbine

The invention provides a blade running state monitoring system for an offshore wind turbine. The system comprises a blade frequency acquisition device for acquiring the blade frequency of the wind turbine, a synchronous driving circuit for receiving the blade frequency and outputting two paths of same driving signals having the frequency in an integer multiple relation with the blade frequency, a light emitting device for receiving the driving signals, emitting light having the frequency same as that of the driving signals and irradiating the rotating blades, a thermal image acquisition device for receiving the driving signals and performing thermal image acquisition in the frequency same as that of the driving signals to obtain thermal image data, and an analysis terminal for receiving the thermal image data and performing fault analysis; the blade frequency acquisition device is connected with the synchronous driving circuit; the synchronous driving circuit is connected with the light emitting device and the thermal image acquisition device; and the thermal image acquisition device is connected with the analysis terminal. The blade running state monitoring system for the offshore wind turbine can timely monitor the blade state of the wind turbine.