In order to effectively guide the selection of scaffold in the designing of cantilever scaffold, a comprehensive analysis of three typical scaffold supporting systems (including fully cantilever, bottom-supporting cantilever and pull-up cantilever) is carried out. The calculation formulas for the internal force of the three scaffold supporting systems are proposed by theoretical analysis methods, which are verified by finite element method (FEM). In addition, the force mechanism and benefits of the three scaffold supporting systems are compared and analyzed combined with actual engineering. The results indicate that there are high calculating accuracy for the proposed internal force and deflection calculation formulas about the scaffold supporting systems. According to the distribution uniformity of the internal force and controlling of the deformation of the main girder, the bottom-supporting cantilever load-bearing system is the best choice. While the pull-up cantilever supporting system is the best choice considering the aspects of cost, construction period and social benefits, which can be popularized in engineering practice.