With the increasing shortage of traditional energy, ship power systems are upgrading and transforming to new energy. However, the uncertainty of new energy output also brings challenges to the economic and safe operation of the system. Based on this, traditional ship energy management is no longer applicable, and a comprehensive energy management system needs to be established. Given this, starting from the new smart ship policies at home and abroad, the development of ship energy management systems in various countries is compared and analyzed. The typical energy management topology and ship micro-grid topology are analyzed, and a major change in the model of energy management is clarified based on the architecture of "Internet + smart energy". The upper-layer energy optimization scheduling, the bottom-layer coordinated control strategy and the application combination with intelligent algorithms of ship comprehensive energy management are analyzed. Oil-electric, diesel engine waste heat, and new energy electric hybrid propulsion schemes are summarized. Finally, it is pointed out that with uncertain energy management and control of ships, establishing a multi-energy coordination mechanism, and using data-driven and multi-level EMS design are the future development trends. This work is supported by the National Natural Science Foundation of China (No. 52077135).