In view of the traditional ship sub-assembly manufacturing technology route, the concept of sub-assembly intermediate product is briefly introduced, the intelligent improvement principle and method of sub-assembly technology route are proposed, and the sub-assembly intelligent production line is constructed. The special stress is laid on expounding the function and operation flow of each station in sub-assembly intelligent production line, and the key technology of sub-assembly intelligent production line is analyzed in detail, which can provide the effective support for improving the efficiency and quality of ship sub-assembly manufacturing.