This invention relates to the field of trestle bridges, specifically to a trestle bridge for construction across railway lines and its usage method. The trestle bridge includes a trestle bridge module, approach bridge modules, a traveling module, and a support and guide module. The trestle bridge module is erected within a reserved passage area on the external track line. The approach bridge module is mounted on one side of the trestle bridge module via a rotating shaft and is pulled by the trestle bridge module. Two sets of traveling modules are installed on both sides of the ends of the trestle bridge module. The support and guide module is erected on the side of the reserved passage area facing the track. The
hydraulic motor in the traveling module, in conjunction with the traveling wheels, drives the trestle bridge module to move rapidly along the guide roller seats of the support and guide module. Combined with the folding and unfolding functions of the approach bridge module, this enables rapid erection and dismantling of the trestle bridge, significantly shortening construction preparation time and dismantling cycle, avoiding prolonged interruptions to railway operations, and effectively solving the problems of long construction cycles and dismantling interference with normal railway operations caused by traditional trestle bridges.