Research methods :On the basis of the error control theory based on the least bi-multiplication and the construction characteristics of Sanmenjiang Bridge in Liuzhou，the linear control model is established with the software of finite- element analysis to ensure the construction quality by using the tested data and results of theoretic calculation.
Research conclusions: The aracteristics of the deflection and change in elevation of main beam structure of partial cable-stayed bridge with super wide deck are close to the stressed concrete continuous box beam. Using the tested data to modify the parameters of calculation model, a perfect match is achieved between theoretic calculation and the real situation of the bridge，which ensures the safe construction of main beam. In the construction , it is necessary to monitor the distortion in real time and adjust the pre-elevation volume according to the weights of the section.
2007, Vol. 24 
