To clarify the research and development direction of shipboard domestic wastewater treatment technology under the background of upgraded discharge standards and differences between domestic and international standards, identify technological bottlenecks, and promote the sustainable development of the industry, this paper systematically analyzes China’s discharge standards for shipboard domestic wastewater, the current application status of treatment equipment, and technological research progress. First, by comparing previous and current discharge standards as well as the indicators of domestic and international discharge standards for seagoing and inland waterway vessels, the core characteristics of increasingly stringent standards and their higher requirements for treatment processes are clarified. Second, through literature review and statistical analysis of discharge data, mainstream treatment processes and the current status of equipment installation are reviewed, and their technical applicability and limitations are analyzed. Third, by combining field surveys and case analyses of typical treatment equipment in the Yangtze River Basin, key technological bottlenecks affecting shipboard application are identified, and the main directions for technological breakthroughs are pointed out. The results show that China’s discharge standards are more stringent than foreign standards in terms of both the number and values of indicators, imposing higher requirements on the multi-objective synergistic removal capacity and operational stability of treatment processes, while conventional biochemical/physicochemical treatment processes can hardly guarantee satisfactory treatment performance. For small vessels below 400 gross tonnage, the installation rate of treatment equipment is extremely low due to space constraints and limited technical adaptability. Membrane bioreactors and electrochemical coupling processes have become mainstream technological directions, but they still face challenges such as insufficient shock-loading resistance, shipboard environmental constraints, and insufficient capacity for digital operation and maintenance as well as supervision. Therefore, a systematic approach should be adopted for the treatment of shipboard domestic wastewater to establish a technical pathway featuring spatial adaptability, stable operation, and simultaneous treatment of blackwater and graywater. Efforts should focus on three directions: synergistic treatment of blackwater and graywater, development of shock-resistant processes, and ship-shore digital operation, maintenance, and supervision. In addition, source-separated reuse and zero-discharge technologies should be taken as important breakthrough directions, so as to promote the coordinated energy conservation, pollution reduction, and carbon reduction in shipboard domestic wastewater treatment.