The metro train induced environmental vibration increasingly attracts people′s attention. By introducing displacement potential functions and Fourier transformation, theoretical solution for the two-dimensional longitudinal track-tunnel-ground model is derived, and compared with the one-dimensional foundation beam model. It indicates that tunnel deflection and ground displacement becomes greater when the tunnel is modelled by Timoshenko beam rather than Euler beam, however, the critical velocity of the 2D coupled model decreases. Larger tunnel buried depth reduces the dynamic displacement of tunnel and ground. In contrast, a larger thickness of the underlying ground produces greater displacement. The floating slab track can significantly reduce the vibration load transmitted to the tunnel but has little effect on the tunnel deflection and ground displacement. 1D track-tunnel-ground model is feasible to determine the vibration load on the tunnel, however, the track and tunnel deflections from these two analytical models are approximate only when the train speed and soil thickness are not large. Otherwise, the deflection discrepancy would be great. The present study has some reference value for the theoretical analysis on the train-induced vibration.