In order to increase the welding automation rate of ship enterprise, the key technologies of sub-assembly 3D structure model processing towards robot welding, complex structure robot welding simulation, and complex structure welding technology database are studied to improve the welding efficiency and quality of ship components. The application scheme of intelligent welding equipment for ship sub-assembly complex structure is defined: to sort out the welding technology process for machining object, to create the technology database with the software to realize the welding data processing, and to complete the control system design and overall structure optimization. The intelligent welding equipment built by the scheme are applied in the shipyards, and the practice proves that the scheme is of strong practicability.