For further research on the dynamic performance of a through tied arch bridge subjected to excitation of moving vehicle loads, a three-dimensional finite element calculation model was established, and modal parameter identification of the arch rib under ambient excitation was carried out for a through tied arch bridge. The precision of calculation model was verified with measured results. The dynamic response of a through tied arch bridge subjected to excitation of moving vehicle loads was studied by finite element calculation model, comfort index of bridge was evaluated on this basis. The results show that the higher the vehicle speed and the higher impact coefficient, and horizontal comfortability of bridge was better while vertical one was poor.