Abstract: Partition walls in the large-diameter shield tunnels of city line mainly bear the horizontal wind pressure generated by trains, and basically do not bear the vertical external load. The above reason makes their top connectors significant components, whose mechanical properties need to be further studied. On the base of Shanghai Airport Link Line, this paper firstly introduces the background detailed including the element of top connector and numerical simulation information. In addition, calculation process of each component of the top connector has been elaborated. Eventually, the stress of top connectors under accidental working condition is calculated and analyzed. The results indicate that, in the future, calculation of the top connector can be carried in the curriculum of no gap between the partition walls and connector, and current design of the weld and bond strength meet the requirements with a certain safety reserve. Moreover, a maximum lateral deformation of 42.17 mm will happen in the partition wall under accidental dropping of top connector.