<p>In order to clarify the influence of particle gradation difference caused by the self-organizing coarsening process of colluvial-deluvial soil on the rapid loss of effective water and insufficient structural stability faced by slope ecological restoration. Taking Jiuzhaigou Panda-Sea accumulation as the research area, the ecological water effectiveness and water migration law of colluvial-deluvial soil were analyzed through soil property tests, water stress tests and water and heat migration monitoring experiments, and the layered reconstruction and improvement were carried out in combination with ecological materials. The results showed that the classification of photosynthetic productivity can more accurately evaluate the ecological water effectiveness of colluvial-deluvial soil. The layered reconstruction model of "Capillary Barrier-Vegetation Growth-Surface Crusts" of colluvial-deluvial soil was established, and the evaporation reduction performance and shear strength of crust were improved by adding modified glutinous rice-based materials. Moreover, the effective water evaporation of the reconstructed improved soil only accounts for 12.51% of the total effective water, and the cohesion and internal friction angle of the crust soil are increased to 274.62% and to 119.77% of the pure coarse-grained soil respectively, the reconstruction modification effect was significant. This study determined the grain size distribution range and applicable combination of colluvial-deluvial soil suitable for slope ecological restoration, and proposed an optimization method for the reconstruction of colluvial-deluvial soil to reduce evaporation and promote stability.</p>