Ad Hoc network is the supporting technology of Tactical Internet, and the performance of a routing protocol is in relation to the efficiency of TI. This paper studies the hierarchical structure of TI, then it points out that flat protocols are not fit for TI while the common clustering algorithms are not considering about the relationship of command in battle. A multi-hop clustering routing protocol is presented here which expands the network scale. Intra-cluster protocol uses the AODV while inter-cluster protocol uses the table driven routing protocol. The result of simulation indicates that this protocol improves the performance of TI.