Based on the study of the main water resources areas and division of the “Belt and Road”, average annual precipitation distribution map and contour lines of the “Belt and Road”were drawn by using the average daily precipitation site data from the Climate Data Online of the National Oceanic and Atmospheric Administration. Based on the precipitation ratio of the main water resources area to the nation, the regional water resources amount is calculated. Combined with the water resources characteristics of “Belt and Road”, the problem of water safety in the district is analyzed, and the framework of water security system with “Belt and Road” features was constructed from the seven aspects of water resources security, water environment security, water ecological security, water engineering security, water supply security, flood defense security and trans-boundary water security. The results show that: the precipitation of the “Belt and Road” is characterized by the spatial distribution of more in southeast part, less in middle, and moderate in northwest, and the density of contour lines of precipitation in different zones is different, showing that there are some differences in spatial characteristics of regional precipitation; the spatial distribution of regional water resources is extremely unbalanced, for example, the ratio of water resources in Southeast Asia to the entire region is as high as 46. 88%, while that in both East Africa and North Africa are less than 1%; the water security situation varies in the “Belt and Road” sub-districts, and the water security issues, which embodied in most areas, are prominent in underdeveloped areas such as Central Asia and Africa. The trans-boundary water security issues are reflected in most areas.