Abstract: There are some problems of Sichuan Qingnan Road Dacheng Railway variable height swivel bridge original design scheme，such as project delay，quality control.Aiming to the particularity and construction feature of construction，it uses overall pouring twice prestress tension optimization scheme.It analyzes optimization scheme prestress construction procedure，control keypoint，and discusses the stand setup scheme comparison and selection，overall pouring attention matters，steel cable prestress and quality control methods and so on.