In order to reflect the synergistic effect and working environment of the long-span steel bridge deck-pavement system truly in laboratory experiments, this paper studies the synergistic experimental model of flexible long-span steel bridge deck-pavement system. Firstly, the local box girder FEM(finite element method) model considering the whole bridge deformation is established. And the deck pavement's stress and strain are analyzed. The entire bridge effect parameter is 1.17. Then, the synergistic experimental model is established.Taking the maximum stress and strain value of local beam section as reference value, the related structure parameters of early model scheme are revised. On this basis, to ensure the consistency of designing for the synergy model and the prototype, stress value of the revised test model and local beam section model in the control point is compared. Eventually, the synergistic experimental model of long-span steel bridge deck-pavement system is obtained in this paper. The results may provide theoretical basis for designing of laboratory experiment model on steel bridge deck.