Abstract:    This paper analyzes and studies the GPS modernization strategy from three aspects. First, it analyzes the internal and external environmental factors of GPS modernization in the United States, points out the essence of GPS modernization in the United States, and then analyzes the content of GPS modernization in the United States, and points out its planning process and advancement situation. Finally, it analyzes the national space security strategy and space policy. The impact of GPS modernization is discussed. This article has some guiding significance to the development of BDS in China.