The invention discloses an articulated transverse moving device of a large displacement expansion device of a medium-low speed maglev bridge, wherein, a terminal rail row structure and a support of the expansion device are respectively arranged on the beam tops of two beam ends of adjacent rail beams;, a simple supporting small longitudinal beam is arranged Between that support of the telescopic device, one end of the simple supporting small longitudinal beam is rotatable and the other end of the simple supporting small longitudinal beam is rotatable and slidable; The upper end of the simple supporting small longitudinal beam is slidably provided with a modular telescopic rail row through a longitudinal beam sliding device; The modular telescopic rail row comprises a plurality of rail rowsub-units; The rail beam and the end rail structure of the rail row subunit are provided with hinged lateral moving devices; Between two adjacent rail row of sub-units and with that end of the rail row structure are equipped with connecting rod devices, the two end of the connecting rod devices are articulated to a hinged lateral moving device including a single-hinged lateral sliding device and adouble-hinged lateral sliding device. The invention solves the problem that the I-type, II-type and III-type F rail expansion joints cannot adapt to the large displacement expansion and contraction of the track beam, and is suitable for the large displacement expansion and contraction of the long-span track beam or the long-link continuous track beam.