Taizhou Yangtze Highway Bridge adopts three-tower suspension bridge scheme which has two 1 080 m main span in its primary design. This paper studies the different displacement traits between three-tower suspension bridge and two-tower suspension bridge. It also analyzes the influence of various parameters, such as the rigidity and height of the tower, the height of the main girder, the sag-to-span ratio and side span's length to middle span's ratio, on displacement feature of three-tower suspension bridge.