Abstract: Manned and unmanned distributed cooperative operations are one of the important combat styles of joint all-domain operations at sea in the future. Therefore, the conceptual connotation and main problems of manned and unmanned distributed cooperative operations at sea are systematically expounded， the current situation of relevant foreign researches is summarized, and three combat modes are proposed: long-wing collaboration, child-mother collaboration, and peer-to-peer collaboration. And an improved distributed cooperative architecture for manned and unmanned marine systems based on multi-agent is proposed. The key technical system of manned and unmanned distributed cooperative operation at sea is constructed and analyzed, which can provide guidance and support for relevant researches in China.