The invention belongs to the technical field of water area monitoring, and especially relates to a sensing method for a water area monitoring multi-element combined sensing system. The system comprises an AIS data processing module, a radar data processing module, a photoelectric guide module, a comprehensive processing module, a multi-target fusion management module, a target comprehensive display module, and a power supply module. The method can achieve the fusion of radar data and AIS data, and achieves the data association of radar equipment, AIS equipment and camera equipment. The sensingmethod solves a problem of target detection and tracking under the complex sea conditions, and improves the target extraction capability. The system employs an advanced multi-source data fusion algorithm for providing high-precision target parameters, collects the data of other sensors for comprehensive analysis and processing while the radar displays a target echo, and achieves the simultaneoussynchronous display of the radar target information and AIS target information.