As a new urban model, the 15-minute city has gradually become a touchstone to measure the future sustainability of cities. With the time-limited planning of urban living circle, urban residents can be allowed to access basic daily needs such as food, health and education while walking or cycling, thus reducing motor traffic and carbon dioxide emissions and contributing to the improvement of people's well-being and the environmental climate. The proposition of building the 15-minute Community-life Circle has been put forward in Shanghai Master Plan 2035. Since 2016, such working standards as Shanghai Planning Guidance of 15-Minute Community-Life Circle, Spatial Planning Guidance Community Life Unit have been continuously released and updated for gradually conducting progressive and incremental circle practices and exploring a path of low-cost, low-emission and low-pollution urban sustainable development. In September 2021, with the theme of 15-minute Community-Life Circle -People's City, SUSAS2021 carried out a two-month urban space art season in 16 communities and 1 theme exhibition area, demonstrating the construction practice of low-carbon life suitable for living, working, traveling, learning and raising in Shanghai.With SUSAS2021 as a specific case, this paper is aimed at exploring a system design method of sustainability concept in the construction of urban life circle with a time limit of 15 minutes. By applying the method of interdisciplinary research, this paper makes a systematic analysis and impact evaluation on its climate adaptability from four aspects: urban renewal, shared community, low carbon living and smart network platform. With the practice results as the research evidence, this paper summarizes the experience of sustainable ecological construction in urban life circle, introspects and discusses the practical problems and comprehensive feedback during the practice, and then puts forward a sustainable system design framework for 15-minute urban construction and a feasible adaptation scheme for studying this method. Under the ever-changing climate environment, the new zero-carbon city model will be an extensively, profoundly systematic change in economic and social development.