In modern air-sea defense intelligent information warfare, the situation awareness is prerequisite and basis to make the aerospace defense battlefield more transparent，reduce complexity of information and improve the command and support capacity of aerospace defense operational commanding. The related problems of air-sea defense is studied, and the demands of data representation，fusion processing，intention reasoning are put forward based on analyzing tremendous threats and challenges of air-sea defense situation awareness systematically. On this basis, considering the autonomous super learning ability of artificial intelligence, the structure of situation awareness based on deep learning is established. And then the key technologies in this structure at the end are expounded, which can provide a new idea for the development of air sea defense situational awareness.