Multi-hop underwater acoustic communication networks (UACNs) are introduced in recent years due to the growing interests of resource developments in the deep ocean. Compare to the terrestrial wireless networks, the UACNs have features of long signal propagation delay and dynamic network topology. Hence, the studies on multi-hop UACNs in recent years usually insist relaying data with dynamic and opportunistic routes to adapt the complex underwater communication structures. However, the studies are difficult to meet the high-traffic underwater applications because the data forwarding with dynamic route requires external time cost in selecting the forwarders, which results in decreasing network performance. Accordingly in this paper, we propose a design of high-speed UACNs to approach the underwater applications with high-traffic and time-critical requirements. The proposed method is based on the underwater full-duplex communication technology, and uses different interference-free channels in relaying data that enables simultaneous sending/receiving in multi-hop UACNs. Different with conventional design of UACNs, the proposed method applies the fixed routes in relaying data on the multi-hop path for the continuous and stable full-duplex communications, and integrates an elimination-based channel evaluation scheme for the route discovery of multi-channel path. Simulation results show that the proposed method has superior performances in adopting high-traffic communications compare to the classic data transmission method of UACNs.