Offshore wind plant pile foundation settlement monitoring system and method

The invention provides an offshore wind plant pile foundation settlement monitoring system and method. A plurality of first pressure difference type static force level gauges are correspondingly installed on the outer wall of the lower portion of a pile foundation through a plurality of level gauge installation supports. A bottom reference seat is fixed on a seabed which is a certain distance away from the pile foundation and is not influenced by the pile foundation; a reference pressure difference type static leveling instrument is fixed on the bottom reference seat; the first pressure difference type static force level gauge and the reference pressure difference type static force level gauge are connected with the concentrator through the first armored cable and the second armored cable respectively, the concentrator is connected with the collecting box, and the collecting box is connected with the control main end. And the control total end is used for analyzing data monitored by the first pressure differe