The invention discloses a light supporting structure for an existing railway station roadbed on a filling roadbed. The light supporting structure comprises a plurality of layers of geogrids, wherein fillers are arranged among the plurality of layers of geogrids; the filling roadbed is arranged under the geogrids. The light supporting structure is characterized in that a reinforced soil baffle wall is arranged on certain sides of the geogrids and a folding-back part is arranged on the geogrids on the sides; the reinforced soil baffle wall comprises a wall body and a panel which are connected by a plurality of anchor rods; the wall body comprises a plurality of covering bodies which fill into the folding-back part layer by layer; the panel comprises a concrete base body, and longitudinal bars and a vertical bar which are arranged in the concrete base body in a criss-cross way, a strip-shaped foundation which is located in the filling roadbed and is arranged under a concrete foundation, and a cap stone located above the concrete foundation; one end of each anchor rod is connected with the corresponding longitudinal bar and the other end of each anchor rod penetrates through the wall body and stretches into the fillers. The light supporting structure has the beneficial effects that with the adoption of the measures, the problem of the difficult rebuilding of the existing railway station roadbed on the filling roadbed is solved, and the technology is simple, practical, convenient and economical.