The invention discloses a two-line rail girder of maglev rail-holding rail transit. The rail girder comprises a left box girder and a right box girder which are erected on a bridge pier, wherein the structure of the left box girder is the same with that of the right box girder, the left box girder is mounted on the bridge pier through a left support, the right box girder is mounted on the bridge pier through a right support, and the structure of the left support is the same with that of the right support; the right side of the left box girder is fixedly connected with the left side of the right box girder through a cross beam, and the cross section of the cross beam is H-shaped; the cross beam is arranged right above the bridge pier and spaced from the bridge pier. The left and right box girders are connected through the cross beam, the overall rigidity is greatly increased, the rail girder is more than 3 times the rigidity when left and right single girders are arranged separately, the structural rigidity is increased, the deformation during structural stress is greatly reduced correspondingly, and the strict requirement of the maglev engineering for structural deformation is met.