Abstract: High speed and secure data relay satellite system based on high power inter-satellite laser links can provide high capacity and seamless relay services for earth observation satellite and user spacecraft with different functions in different orbits, it has a broad prospect of application both in military and civil fields. The European countries have studied the data relay satellite with laser links, the theoretical research and technology demonstration on-broad is launched, and so is the corresponding engineering verification program. In this paper, the research progress was demonstrated and reviewed; typical data relay satellite system based on inter-satellite laser links was introduced, especially in the system structure, the hardware and experimental foundations. The prospect of the inter-satellite laser links networking toward advanced applications was expected.