The Belt and Road initiative, involving 65 countries with a total population of 4.4 billion, is not only a major national strategy but also an international initiative characterized by wide ranges, long-term, and diverse fields. In the context of the regional and global challenges of sustainable development brought by environment protection, resources, energy, hazard risks, and global change, this study aims to explore how space-based Earth observation technology can support to deal with those challenges by examining the advantages and capability of this technology. And then the establishment of a Digital Silk Road based on the spatial observation is further proposed, which will promote the S&T and overall cooperation between China and the other related countries by providing spatial data, environmental information, and decision support. Digital Silk Road will definitely serve and contribute to the construction of the centurial project, One Belt and One Road.