Pisha sandstone, characterized by high compressive strength when dry but rapid disintegration upon exposure to water, presents significant challenges for engineering projects in Inner Mongolia, China. Traditional erosion control measures, such as slope leveling and concrete surfacing, have proven ineffective, resulting in substantial soil loss and sedimentation. This paper introduces a novel composite ecological slope protection technology designed specifically for Pisha sandstone regions. By utilizing improved soil with enhanced water retention properties and integrating a grid net secured with the natural shell layer of Pisha sandstone, the proposed method significantly increases plant survival rates and enhances the stability of the root-soil complex. This approach increases shear strength from 66 kPa to 216 kPa and increases water storage capacity by over 33.53%, which promotes the growth of roots and the improvement of shear strength. Consequently, this innovative solution markedly improves the erosion resistance of slopes. This combination of measures integrates engineering with ecological solutions. It was confirmed that the biological survival rate is high by experiments. The early engineering measures offer vital support for biological growth, while in the later stages, biological methods mainly focus on slope erosion protection. After implementation, the overall outcome aligns with the local ecological environment and demonstrates remarkable ecological benefits.