Water conveyance tunnels located in the northwest cold region are impacted by the drift ice to different degrees during the drift ice period; however, the water in the tunnel as a medium has an inhibitory effect on the collisions between the drift ice and the tunnel lining. Therefore, in order to study this effect of small and medium drift ice, we chose No.37 Pandaoling Tunnel of the Datong River to Qinwangchuan Region Water Transfer Project as the research subject. Drift ice-water conveyance tunnel collision models based on the additional mass method and fluid-structure coupling algorithm were established to study the dynamic response of the water conveyance tunnel lining to the collisions caused by drift ice, combined with the finite element software LS-DYNA. The research show that the high stress zones of the tunnel lining in two collision models are different to some extent due to the action of water medium. When using the additional mass model to simulate the impact of drift ice on the water tunnel, the calculation results are generally larger, but it has the advantages of simple modeling and short analysis time. As for the fluid-structure coupling model, which takes into account the dynamic water action in the collision process and the “water cushion effect” generated when the ice approaches the water tunnel, it can better simulate the actual collision scenarios between the drift ice and the water tunnel.