Accurate calculation of manufacturing parameters is the key to the efficient，high-precision，and rapid installation of large sections of continuous steel box beam bridges.Taking the steel box beam with the variable section in Shenzhen-Zhongshan Passage as the background，this paper first established a finite element model of the beam element in the whole construction process to obtain the pre-camper.Secondly，the average neutral axis position was calculated based on the height of the neutral axis of each beam section.Then，according to the deformation characteristic that the beam length remained unchanged at the mean neutral axis，the pre-camber was superimposed at the mean neutral axis to get the manufacturing line shape.Finally，according to the mechanical characteristics，the dip angle of the large section end face was given to obtain the complete manufacturing parameters of the steel box beam.The implementation results before the loading of the second-phase dead load show that the line shape of the top surface of the steel box beam is generally smooth，and the measured line shape is in good agreement with the predicted line shape，which verifies the correctness of the proposed method.