The concepts, components and organizations of ship information infrastructure (SII) are important issues in the engineering domain because the development of new-type SII brings new features to ship combat systems and professional applications. In this study, the key characteristics of SII in different phases are analyzed; the constituents and functions of the total ship computing environment infrastructure of the U.S. Navy are described emphatically; the concepts and architecture of SII are described in terms of the development laws of ship combat systems; the new development and integration models of the professional applications and combat systems of ships are deduced; and the key features of SII are defined. The new development trends of SII are analyzed on the basis of professional application model trends, SII construction and cutting-edge information technologies. As the foundation of ship information systems, high-level SII construction can give full play to the combat systems and professional applications of ships, thereby increasing their combat effectiveness.