Abstract: Based on Hamilton principle, a cable-tunnel coupling vibration model of submerged floating tunnel (SFT) is established considering the angular displacement of the tunnel and the difference between the dynamic tensions of cables on both sides. The model and the MATLAB solution program are verified by finite element software. The vibration responses of the tunnel and the cable are analyzed combined with the existing SFT cases. The results show that the theoretical calculation model established in this paper is in good agreement with the finite element model, which can provide theoretical solutions for the calculation of angular displacement and torque of the tunnel, and make the calculation results of cable dynamic tension more secure. The angular displacement of tunnel gradually increases from two sides to the middle, but the torque of tunnel at the anchorage point of the cable is obviously larger than that at other parts. When the cable is subjected to asymmetric load, ignoring the difference between the dynamic tension of cables on both sides will make the calculation result of the cable’s vibration response smaller. Under the seismic load, only odd-order modes participate in the vibration of tunnel, and even-order modes are not excited. When using the mode superposition method, in order to ensure the calculation efficiency and accuracy, it is recommended that the SFT with a span of 500 m or more be calculated with the modal orders above 7, while the SFT below 500 m be calculated with the first 7 modal orders.