The integral mechanic model of the non-loading rail cable launching system was established to deal with the stiffening girders construction in suspension bridge. The rail cable segment was discretized into two-node line element. And the governing equations for the rail cable launching system, which consists of the main cable, the sling, the saddle and the rail cable, were determined. Moreover, a 1∶33 reduced-scale experimental model for the rail cable launching system of Aizhai suspension bridge was constructed. The conclusions obtained from the theoretical analysis and experiments were compared. It is shown that the results of presented calculation method match well with that from the model test. Also, the accuracy and effectiveness of the proposed method are manifested, which can be used to solve the problem about rail cable launching system and simplify the calculating process. The calculation accuracy and results for this method can be employed to the initial-state analysis. This indicates that the recommended analytical method is suitable for shape-looking calculation and analysis of the non-loading rail cable launching technology.