The purpose of this study is to develop the control technology of global distortion in the deck of superstructures during manufacturing processes. The behavior of global distortion in the deck was evaluated by FEA and verified through comparing with the measured results by 3D measuring instrument. It was seen from the results that the principal factor inducing the global distortion is to be the bending moment associated with the longitudinal shrinkage force and transverse shrinkage caused by welding of stiffeners and flame heating to correct the excessive local out-of-plane distortion. Based on the results, the amount of reverse distortion in the thin deck plate was determined to control the global distortion in the deck plate. The proposed distortion control technology was verified by applying it to the actual structure.