The development of green, economically viable modified loess geopolymer materials (MLGM) addresses the current shortage of effective, sustainable slope protection materials for sediment retention dams on the Loess Plateau. The approach facilitates reduced soil erosion, energy conservation, and emissions reduction. This paper investigates the feasibility of producing environmentally sound, cost-effective slope protection materials using loess, solid waste (blast furnace slag, fly ash, silica fume, steel slag), and alkaline modifiers. Experiments investigated the effects of solid waste types, curing temperature and duration, and water erosion ageing on the mechanical properties, softening coefficient, and hydration products of MLGM. Results indicate that solid waste enhances both the mechanical properties and softening coefficient of MLGM. Among these, blast furnace slag demonstrated the most favourable modification effect. Specifically, at a 20 % blast furnace slag content, the 28-day compressive strength and 28-day water erosion softening coefficient reached 22.79 MPa and 0.63. Increasing curing temperature enhances the early strength development of MLGM. However, curing temperatures exceeding 80 degrees C adversely affect the compressive strength development of FA20/MLGM and TS20/MLGM. Modifiers promote the dissolution of active Ca2 + , Si4+, and Al3+ ions, which participate in hydration reactions and geopolymerization reactions to form C(-A)-S-H and N-A-S-H gels. Although elevated curing temperatures do not generate new mineral phases, they reduce the peak intensities of feldspar and calcite. Furthermore, they accelerate the hydration reactions and geopolymerization reactions processes within MLGM.