Abstract: There is great heterogeneity between operation unit of different branches of army. It's important to solve the connection in operation unit. A method for modeling the correlated interaction protocol is proposed. By using the concepts, attributes, association relationship and instance in ontology language a structural Metadata system to unify the description method for interaction protocols of operation unit is established. Some association relationship of operation unit, operation unit status and interaction protocols. It can provide the same gene of data and logic foundation for tactical data, packets and situation in terms of the integration in branch of army and fire control are also established.