Abstract: Considering the highly dynamic and non-stationary characteristics of maritime communication channels in 6G, this paper proposes a secure channel modeling method that integrates physical mechanisms and intelligent algorithms. The sparse characteristics, atmospheric duct effects, and other channel features of the maritime environment are analyzed along with their security challenges. Spatial scattering-based channel models are established for three typical scenarios: satellite, unmanned aerial vehicle (UAV), and coastal base station–ship communications, incorporating key technologies such as reconfigurable intelligent surface (RIS), multiple-input multiple-output (MIMO), and fluid antenna system (FAS). An intelligent optimization-based communication framework is constructed to achieve secure multi-stream transmission and covertness enhancement in low-rank channels. The research results provide theoretical and technical support for the highly reliable and secure deployment of 6G maritime communication systems.