Corrugated steel web-PC (prestressed concrete) composite box girder originated in France in the 1980s, was accepted and popularized in Japan in the early 1990s, and has become the recommended bridge type for Japan's expressways now. In recent years, the domestic corrugated steel web PC box girder has been gradually applied to the long-span continuous beam bridge and cable-stayed bridge from the small and medium span at the beginning, and the commonly used construction methods are bracket method, cantilever method and push method. The construction of the closure section, as the most critical working procedure of the cantilever construction, is directly related to the linearity of the main beam and the overall stress state of the bridge.