To decrease the energy loss when the crane dolly climbing and smooth its move track, the arch curves of girder were studied. Geometric model of the structure was simplified reasonably according to crane bridge structure characteristic, and the finite element models of the girder with different arch curves were established. The downwarping values of the girder with different arch curves under the rated load were obtained by simulation analysis, and further the move track of the crane dolly could be drawn. Also, the advantages and disadvantages of the arch curves were discussed. Taking maximum smoothness of the move track of the crane dolly as research object, a better arch curve was obtained by shape optimization. The research can provide a basis and reference for the arch curve design of the crane girders.