Objectives   In order to realize the digitalization, networking and intellectualization of ship steam power systems, this paper puts forward an application system based on a digital twin model.

  Methods   The "four-dimensional thought model" of a ship steam power system based on a digital twin is proposed, covering the four dimensions of physical object, process element, life cycle and virtual space. The "five order system model" of the whole life cycle of the power system is then established, including five typical stages: concept demonstration, system design, general assembly and construction, trial run, and operation and maintenance. Advanced technologies such as big data, internet of things, cloud computing, artificial intelligence and model-based system engineering are introduced, and the overall digital twin "seven-layer architecture model" of a ship steam power system is formed, composed of the physical layer, interface layer, data layer, model layer, scheduling layer, function layer and application layer.

  Results   The verification results of the virtual design analysis and test platform of the ship steam power system show that the digital twin system framework can effectively support the system's scheme design, operation analysis and test scheme evaluation, and realize interaction and cooperation between the physical space and virtual space throughout the whole life cycle of the ship.

  Conclusions   The results of this study can provide valuable references for the overall digital design of ship steam power systems.