The invention discloses a straddle type monorail transit fixedly-connected double-rail-beam and belongs to the field of monorail transit. The double-rail-beam is provided and composed of two webs anda bottom board in a combined mode, the bottom board is located in a certain position between the lowest end and the upmost end of the two webs, so that the effect that the overall rigidity of the double-rail-beam is improved is achieved, meanwhile, the problem that a single rail beam is likely to fall during an earthquake can be solved through the double-rail-beam connected through the transversebottom board, and the anti-seismic capacity of a rail beam bridge structure is greatly improved.