Bridge deck construction method for large-span highway-railway dual-purpose steel truss girder bridge

The invention discloses a bridge floor construction method for a large-span highway-railway dual-purpose steel truss girder bridge. The bridge floor construction method comprises the following steps that S1, skip pouring is conducted on a positive bending moment area of a highway bridge floor on the steel truss girder bridge after closure is completed; the skip bay pouring is divided into a preset number of batches, each batch is symmetrically and simultaneously carried out in the direction from the side span to the middle span, and each batch is spaced by a preset time length; s2, construction of a lower-layer railway bridge deck is conducted; s3, carrying out preloading with preset weight on the side span of the bridge; s4, concrete pouring of the negative moment area of the highway bridge floor is conducted, and bridge floor pouring closure is completed; s5, unloading the heaped load of the bridge side span; and construction of the highway-railway dual-purpose bridge deck is completed. By means of the meth