In a performing art center project, the roof system uses steel trusses with large-span, which challenges the installation of trusses in construction. Two SCC400 hydraulic crawler cranes are arranged to lift roof trusses. Since it is impossible to sustain the huge cranes for structural slabs, an independent steel trestle will be constructed along the moving path of cranes. The steel trestle is a special frame system with three kinds of levels. Constrained by constructed basement structures, steel trestle has a complex shape and some long span members. It requires some members high capacity and stability. To investigate its mechanics properties, especially the whole stability, a set of analysis, including static and elastic buckling analysis, are carried out on this steel trestle by use of ANSYS software. According to the working conditions of crawler cranes, the loads caused by walking of cranes and hoisting trusses are considered. On the basis of the static analysis, the dangerous loading areas are determined to conduct eigenvalue buckling analysis. The results show that the loads in different positions have less impact on the force and deformation of the entire structure. The buckling characteristic value of the first four modes in both load conditions is larger than 1, which indicates that the system has enough stability.