Research conclusions:The horizontal natural vibration period cycle was controlled because of the large span and narrow width of the beam＇s box． Based on the analysis of the parameters，the analysis of the influences of the pier width，the box width of the beam，the slope of the pier and the horizontal layout of pile foundation on the natural vibration period of the structure were analyzed comprehensively． The double wall piers with the longitudinal straight slope and variation of lateral slope were designed to make sure the structure had enough lateral rigidity while the longitudinal stiffness of the could be reduced effectively，the requirement of load bearing for the large span continuous structure could be met，the transverse joint in double － wall piers could be cancelled and the structure could be of more lightweight with good looking appearance． In beam design，the layout of longitudinal prestressed steel strand was optimized ，the upwardly curved steel strand in the web was cancelled，the principal tensile stress was overcome by the longitudinal steel strand and the vertical prestressed steel to avoid the crack of the web of large span structure．