The horizontal running tracks of the front and middle outriggers must be laid horizontally, and the spacing must be strictly controlled. The two tracks must be parallel. Before the bridge erecting machine travels, check the track laying condition of the bridge erecting machine. The track gauge error of the bridge erecting machine shall not exceed 2 mm, and the height difference between adjacent track joints shall not exceed 1 mm. The track shall be fixed on the sleepers with spikes to ensure that all sleepers are under stress. , it is prohibited to use sleepers that have been scrapped; the limit blocks are installed firmly. The sleepers on the cover beam are adjusted according to the cross slope of the bridge to ensure that the cross slope of the rail is <0.5. The sleeper stacks are set up according to the specific conditions and require stability and reliability. The distance between sleepers should not be greater than 30cm. Before the bridge erecting machine is started, the height of the front and middle legs should be adjusted so that the main beam of the bridge erecting machine is horizontal or deflected upward by 5-10cm. If the structure cannot be guaranteed, during the girder erection process, a winch should be hung at the rear of the prefabricated beam to pull it. Prevent precast beams from sliding down.