The rapid development of the shipping industry has made energy consumption and environmental problems of traditional ships increasingly prominent. Considering the carbon peaking and carbon neutralization goals and the Initial IMO Strategy on Reduction of GHG Emissions from Ships, ammonia-hydrogen powered marine ships will become an important development direction for waterway transportation vehicles. This study explores the demand for and the international development status of ammonia-hydrogen powered marine ships and analyzes the key technologies, involving ship safety, fuel filling, hydrogen production from ammonia reforming, power production from ammonia and hydrogen, hydrogen production from renewable energy, ammonia synthesis based on renewable energy, and treatment of harmful pollutant discharge. Moreover, staged goals and upper/mid/lower-stream industrial elements are examined based on China's national conditions. To promote the sustainable and innovative development of ammonia-hydrogen powered marine ships in China, we propose the following suggestions: (1) implementing special plans for an ammonia and hydrogen fuel supply system and the infrastructure construction of ammonia-hydrogen powered marine ships, (2) strengthening the maintenance of supportive service facilities, and (3) accumulating engineering experience to provide support for the subsequent large-scale industrial chain and infrastructure construction.