In the process of stiffening girder construct ion of a long-span steel truss girder suspension bridge，different connection modes of stiffening girder segments will directly affect the internal force，alignment，and bridge state of the structure during construction.By taking the construction of the stiffening girder of a bridge as the research background，the finite element model of the whole process of the bridge was established.The advantages and disadvantages of the segmented hinge method and the segmented rigid connection method were compared，and the two-two segmented rigid connection scheme was proposed.On this basis，according to the changing law of steel truss section alignment and lower chord opening in the process of stiffening girder hoisting，the idea of synchronous operation of “rigid connection for small segments + rigid connection for large segments ” was put forward.In addition，the system conversion process scheme between stiffening girders was developed and implemented.The test results of the real bridge verified the correctness and feasibility of the analysis method in this paper.On the premise of ensuring the safety of the structure and the reasonable state of the bridge，it could save the construction period and reduce the construction cost.