The invention relates to a novel submarine cable water area AIS target detection method. The method comprises the steps that AIS data sent by a ship around a harbor area is received, the water area ofthe harbor area is subjected to hierarchical gridding, and a ship ID is associated with coordinate positions of different levels; the AIS data is screened according to a time interval and a selectedtarget area, grid processing is carried out on the target area, and the frequency of the ship at different levels of grids is calculated to obtain a ship distribution frequency histogram; an image model is built by utilizing ship position information, the ship sailing trend is predicted by using a discrete random distribution Markov prediction model, and a prediction curve of the navigation trackof the target ship is formed; the information of the ship near the high-grade warning water area is extracted, and the information of the ship is identified in a graded grid chart of the harbor area,wherein the information of the ship includes the ship ID, the course and the navigational speed; a VHF radio station is controlled to broadcast to the ship near the high-grade warning water area. According to the method, the safety of the submarine cable water area is improved.