Abstract: Deep Green is a C&C project supported by DARPA, which is a brigade level system used for USA Army. Deep Green use AI in operation decision support systems by convergence of information, function and procedure, which is supported by some key technologies such as sketch to plan, model solving and situation forecasting, system integration technology. But Deep Green doesn't reach the expected effect, it encounters many difficulties, for example input and output of situation and decisions, simulation of future, data problems, coordination between human and computer, Army difficulties. The future of decision support system is dependent on technology of AI, deep learning and data to decision, finding the way to solve different problems. The key point lies in awareness of battlefield situation, behavior modeling, decision selection and feedback.