Abstract: By taking a high-speed railway prestressed concrete continuous girder bridge with spans of 48 m+80 m+48 m as an example, the effects of the model refinement of ballastless tracks on the seismic vulnerability were analyzed. The software OpenSEES is used to build four track-bridge models with different model refinement levels of the ballastless tracks. A large number of vulnerability curves of the bridge and track components were obtained. The results show that the seismic vulnerability curves of the sliding layer are greatly influenced by the model refinement of track structure. As the model refinement of track structures is reduced, the failure probability of the sliding layer increases, while it has less influence on the vulnerability curves of the sliding bearing and the pier. Similarly, the sliding bearings are a little more vulnerable with the less refined ballastless track model. On the contrary, the piers are a little less vulnerable. In addition, the model refinement of track structures has feeble influence on the seismic vulnerability curves of the CA layer, fasteners, piles and other components.