Building permanent transportation corridors across vast and deep water is still a great challenge in the field of bridges and tunnels all over the world. Rigidsupported submerged floating tunnel is an option to which special attention is worth to be paid. The design concept of twoway force and combined structure is adopted for rigidsupported submerged floating tunnels. Lateraljacked antiuplift steel piles are used as the fixing and supporting structure of the tunnel tube. The cost of the rigidsupported submerged floating tunnels per lane is less than half of that of bridges and tunnels. In case of rigidsupported submerged floating tunnel, no earthwork is executed and no pollution is produced. Furthermore, rigidsupported submerged floating tunnels are easy to be constructed. Taking Qiongzhou strait transportation corridor as an example, the author presents the basic structure, mechanical principle, construction method, safetyguarantee measures and solutions to some key problems of rigidsupported submerged floating tunnels. The paper can provide reference for the building of permanent seacrossing transportation corridors in the future.