Firstly the principle of INS/CNS/GNSS integrated navigation is introduced, and then the development and application status of INS/CNS/GNSS integrated navigation technology is analyzed. At last, several research directions of INS/CNS/GNSS integrated navigation technology are proposed, which include the information fusion and advanced filter of INS/CNS/GNSS integrated navigation, the real-time ability of INS/CNS/GNSS integrated navigation and INS/CNS/GNSS integrated navigation technology based on integration. With the rapid development of INS, miniaturization of celestial sensor and high performance GNSS, as well as the depth research of advanced information fusion, integration algorithm optimized and system integration technology, INS/CNS/GNSS integrated navigation technology will get further development and play an important role in multiple application fields.