In order to study the effect of structural connections on static performance, influence lines of three-pylon suspension bridges were analyzed. The Taizhou Yangtze highway bridge was a prototype, and its influence lines of structural response were calculated by limited displacement method, considering different cable-girder connections and pylon-girder connections. The effect of structural connections on the influence lines was also researched. The results show that, when center buckles were not assembled in three-pylon suspension bridges, the change of pylon-girder connections had an unobvious effect on the influence lines, including middle-span deflection of the girder, horizontal displacement at the top of pylons, and different value of main cable sided on the middle saddle. Also, when center buckles were assembled, the influence lines were changed remarkably, especially to amplitude in the part of local span, and to the shape in the part of adjacent span. Based on the variation of influence lines, the recommended structural connection for three-pylon suspension bridges was the rigid center buckle coupled with elastic stringer.