The invention discloses a system for monitoring a free state and an anchoring state of floating docks. The system comprises a plurality of monitoring nodes for monitoring different floating docks respectively and a monitoring center, wherein each monitoring node is connected with the monitoring center through optical fiber; each monitoring node comprises a data acquisition unit, a central processing unit, a node display unit, a node alarm unit and a node optical fiber transmitting / receiving unit; the monitoring center comprises a center optical fiber transmitting / receiving unit, a center display unit, a center control unit and a center alarm unit; and the central processing unit comprises a data acquisition unit, a data processing unit, a state judgment unit, a node control unit and a storage unit. The system is specially applied to the special monitoring objects, namely the floating docks, can analyze and calculate the acquired and detected state data, has pertinence, and is comprehensive, perfect, accurate, reliable, convenient and practicable.