The topic of the paper is the numerical investigation of steel-concrete composite trusses with the aim to analyse the behaviour of the shear connection at the steel-concrete interface. In case of composite trusses due to the tension-compression forces acting in the web members the shear connections are subjected to combined shear-tension or shear-compression. The focus of the papers is to find a novel shear connection capable to carry the combined forces with the final aim to provides structural solution for a composite truss applicable in composite floor system. The first step of the numerical research is to develop an advanced numerical model using Ansys software to analyses the local structural behaviour of different shear connection types (headed studs and perfobond plates). The results of the local FE model are verified by experimental results of push-out tests completed in the Structural laboratory of Budapest University of Technology and Economics, Department of Structural Engineering. After the detailed understanding of the local structural behaviour of shear connections and model verification, the global FE model of a composite truss is developed spanning 15 m in simple supported configuration, consisting of a concrete slab in compression combined with steel web members and steel tension chord. The aim is to analyse the global behaviour of the truss and to focus to the connections between the concrete slab and the steel web elements. Two type of shear connections are analysed: headed studs and perfobond plates. Since the headed studs are not supposed to be applied if significant tensile force acting to the studs, the novel shear connections of perfobond plates are in the focus of the research. Two types of perfobond plates are studied: flat perfobond and Y-shape perfobond plates to accomplish a ductile global structural behaviour of the truss. The paper concludes the results and provides recommendations regarding the application perfobond plates for composite trusses.