More natural, effective and collaborative human-computer interaction is the request of human-computer environment in C2. In this paper, the elements of human-computer interaction in C2 were analyzed, and the concept model and system model of multiple and multimodal HCI were proposed. Based on the models, a prototype system was designed to accomplish the tasks of situation or intelligence analysis by two interaction channels, which are speech and two-handed gesture based on multi-touch. The improvements of naturalness, efficient and collaboration for the prototype system were proved with experiment and questionnaire, and the results show that the multiple and multimodal interaction in C2 is effective.