As a fast and efficient bridge construction method,the rotating construction of cross-railway bridge is favored by design and construction units.In order to ensure safe and smooth progress of the rotating process,the overall balance of the bridge before the rotating construction becomes a crucial part.It is necessary to carry out weighing tests on the bridge and find out the center of gravity position of the whole bridge.When the eccentricity is serious,it is necessary to adjust the center of gravity to the center position of the ball hinge by increasing the counterweight.Based on the construction monitoring project of horizontal rotation process of Jining Xinyan railway vertical bridge,this paper studies the principle and practical operation of horizontal rotation bridge weighing test.By applying supporting force on both sides of pier top,the relationship curve between force and displacement is observed,and the stress state and eccentricity of rotating body are obtained.The results show as follows:The unbalance moment of the left and right amplitude of the rotating bridge is less than the static friction moment of the ball hinge,and the eccentricity is small,which meets the requirements of the rotating construction.