The research firstly investigates the background of senior living communities and sustainable design, underlines the relationship between population ageing and sustainable development, as well as the necessity of the research. Then, case studies were conducted on sustainable senior living communities in three developed countries with an already aged population, including the United States, Spain, and Australia, to figure out the design paradigms applicable to China. Both quantitative and qualitative methods were employed for questionnaire surveys, user interviews, and behavioral observation on elderly people, after which their characteristics and needs were analyzed. Finally, a method for the sustainable design of senior living communities was obtained, featuring the sustainable design model of “systematic design: community-centered; environmental-friendliness: harmony-seeking; cost reduction: sustainability-guided; humanity: behavior-oriented”, which provides new inspiration for the improvement of the quality of life in senior living communities.