As one of the current research hotspots in artificial intelligence, deep learning has received widespread attention. With the powerful feature representation and learning capability, the deep learning has increasingly become the technical basis for the development of intelligence in the military field. In combination with the latest development of deep learning, this paper points out that the rapid development of deep learning is attributed to the breakthrough of theory, the remarkable improvement of computer computing power and the widespread popularity of opensource software, focuses on combing the current main deep learning hardware platforms and programming frameworks, and summarizes the characteristics and research progress of each. Further, the application and shortcomings of the deep learning in typical military areas such as target recognition, situational awareness and command decision are summarized. Finally, the challenges faced by military application of deep learning are analyzed, including difficulties in data acquisition, insufficient ability to handle uncertain and incomplete information and multidomain information, low accuracy and realtime, and poor interpretability and comprehensibility. In view of such challenges mentionedabove, the paper looks forward to the future, the possible development directions, and the trend.