With the continuous development of modern bridge aesthetics，the asymmetric special shaped section girder is becoming more and more widely used in landscape bridge and pedestrian bridge. However，the aerodynamic performance is significantly affected by the shape of the section. Based on the engineering background of a special-shaped box girder cable-stayed bridge，the vortex vibration performance of the main girder was tested in the wind tunnel. In test，the splitter plate was added at the railing，the cross section nozzle of main beam was installed，and the shape of railing was changed. The results show that the obvious vertical vortex vibration is induced within the design wind speed，and the vibration exceeds the maximum amplitude specified in the code. The vortex-induced vibration will be restrained by flow suppression plate at the railing，when the blunt face of the main girder is windward side. However，the negative effect can be caused，when the non-blunt face is windward side. Furthermore，the similar results are obtained by installing the cross-section nozzle of the main girder. By changing the shape of the railing and installing the air nozzle，the vortex induced resonance of the main girder can be successfully suppressed，and the requirement of flutter stability can be met.