In this paper, the composite structure of continuous prestressed concrete girder with concrete-filled steel tube arch under span arrangement (90 + 180+90) m is cited as an example, which is the superstructure of Beijing-Hangzhou Grand Canal Bridge in Beijing-Shanghai High-speed Railway at Zhenjiang. Then, focusing the stress and deformation characteristics of long-span continuous girder-arch system under construction stage as well as completion stage, several issues are researched such as the key construction processes, long-term creep deformation characteristics and geometric control of the continuous girder. Also, the paper gives the presetting height values for all segments of the main girder. The research results show that, between theoretic value and measured value during whole processes of construction of the main girder, the maximum elevation difference is 12 mm, and the elevation differences of the most of elevation control pints are less than 10 mm, so the elevation differences meet the requirements of design and geometric control. Furthermore, in the stage of construction, the accumulated stress differences between theoretic value and measured value on all test sections of whole bridge are less than IMPa, and the girder body is basically under the condition of axial compression; and in the stage of completion, the stress state of the continuous girder is good.%京沪高速铁路镇江京杭运河特大桥主桥上部结构为(90+180+90)m预应力混凝土连续梁与铜管混凝土拱组合结构,以大跨度连续梁拱体系施工、成桥阶段的受力和变形特征为着入点,针对桥梁的关键施工控制工序、长期徐变变形特征、连续梁线形控制等方面进行研究,给出了主梁各节段前点预抛高量设置值.主梁施工全过程中理论高程与实测值最大差值最大为12 mm；绝大多数高程控制点理论值与实测值相差均小于10 mm,满足设计及连续梁线形控制要求.全桥施工阶段各测试截面的理论与实测累计应力差值均小于1 MPa,梁体基本上成轴压状态,连续梁成桥状态下的应力状态很好.
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