Submerged floating tunnel is a novel sea-crossing structure suspended under the water. In order to analyze the dynamic response of the submerged floating tunnel subjected to moving load, a submerged floating tunnel is simplified as a spaced beam on elastic supports. Considering the fluid inertia effect and damping effect by Morison equation, it is proposed that the dynamic differential governing equations of the submerged floating tunnel subjected to moving load through modal superposition and Galerkin methods. Meanwhile, the numerical examples are mentioned to solve dynamic differential equations by using the fourth-order Runge-Kutta method. The results show that the impact coefficient and acceleration response of structure are related to the fluid effect. Furthermore, the fluid effect is affected by the length of structure and mode number. Besides, the tether stiffness is disincentive to the impact coefficient and acceleration response. Moreover, high speed moving load will result in the structure more dramatic fluctuation.