Abstract: The double-skin multi-cavity composite wall consists of two external steel plates and infilled concrete. Mechanical connectors are used to enhance the composite action between the two materials. In the paper, a new truss connector was proposed, which can effectively delay the buckling of the steel plate and improve the overall performance of the wall. The ANSYS finite element software was used to simulate the wall performance, and the validity of the finite element model was verified by comparing the experimental data. Parametric analysis was carried out to study the influence of key parameters such as steel plate thickness, truss spacing and wall height-thickness ratio on the wall performance. The results showed that increasing the thickness of the steel plate could delay the buckling of the steel plate and increase the bearing capacity of the wall; increasing the truss spacing would reduce the restraining effect of the truss on the steel plate and the bearing capacity of the wall; changing the height-thickness ratio of the wall would affect the failure mode of the wall.