Cross-domain unmanned cluster is a disruptive new combat mode in the future, and its combat effectiveness is greatly affected by communication networking capabilities. In recent years, satellite Internet, with its technological advantages of wide coverage, low latency, high bandwidth, and low cost, has developed rapidly in the world, and it is the key to further developing the cross-domain unmanned cluster combat mode. In view of the development trend and practical needs of the future unmanned undersea system, the development and technical advantages of satellite Internet, as well as the concept of cross-domain unmanned cluster combat were introduced. The advantages of cross-domain unmanned cluster combat supported by satellite Internet were deeply analyzed. The air-sea cross-domain unmanned cluster combat network was proposed by combining satellite Internet technology and unmanned clusters in airspace, sea surface, and undersea combat domains. In addition, a comprehensive analysis of the technical architecture was given, providing a reference for future research on cross-domain unmanned cluster combat.