Abstract: During the quieting process, a submarine faces the new energy differences of radiated noise. The theory of structure-borne noise must be deeply analyzed and applied as it is one of the most indispensably important theories for Chinese submarines to achieve transcendence. However, if hope is still pinned on improved raft vibration isolation, greater structural rigidity, higher damping or refined construction, the probability of success is almost nil. Researchers must adopt new thinking about structure-borne noise in order to decode the inherent acoustic passwords of structures and reconstruct the complementation characteristics, overlay characteristics and functional design of complex and huge submarine systems, thereby controlling energy input, internal wave conduction and acoustic radiation. As a theoretical tool for solving the "last kilometer" of submarine quietness, this is the core value of structure-borne noise with logically subversive significance.