Abstract ： Research purposes ： The early crack during construction stage is very widespread for large span prestressed concrete box girder bridges. These cracks which have adverse effects on the safety operation and durability for bridge， should be controlled in the construction stage. Based on the North Beach Bridge of Jingyue Yangtze River Highway Bridge，studyin order to effectively control thecracks in theconcrete box girder construction with experimental research，theoretical analysis and construction practice aiming at the structural characteristics of thin walled box girder is carried out. Research conclusions ：( 1) Based on experimental research and theoretical analysis，the development law of hydration heat，the reasonable prestress tension age， corrugated pipe and grouting technology of the Nortli Beach Bridge are ascertained. (2) The mix ratio of concrete is optimized and the quality of raw materials is guaranteed， concrete construction process and maintenance details is attached great importance to ； the hydration heat is controlled ； the effective prestress and prestress tension age is ensured ； and the prestress corrugated pipe and grouting material is optimized. The crack resistance system throughout the design, construction； monitoring and management of the whole process is developed. (3) No crack is found in Beach Bridge in the third party acceptance. It is shown that the crack control system can efectively prevent tlie early cracks for large span PC box girder bridges. The engineering experiences can provide references for similar bridge engineering projects.