Red clay water-destroyed side slope protection structure capable of reducing abandoned side slope

The invention discloses a red clay water-destroyed side slope protection structure capable of reducing an abandoned side slope. The protection structure comprises step foundations and a combined protection structure. The step foundations are arranged at intervals, are built and formed by mortar rubbles, and correspond to the positions of the bottom surfaces of vertical beams in the combined protection structure; the combined protection structure comprises a combined beam and a back pressure backfill soil body structure, the combined beam comprises cross beams and vertical beams which are arranged in a staggered mode, the cross beams are cast-in-place reinforced concrete cross beams, the vertical beams are cast-in-place concrete vertical beams, and the back pressure backfill soil body structure comprises a gravel bag layer, a soil bag layer and vegetation bags. The surface of the whole back pressure backfill soil body structure is anchored through a U-shaped anchor nail. The invention further discloses a prote