Ecological slope protection serves as the primary technique for promoting slope ecological restoration and reducing geological hazards. Based on ecological environmental theory and geological disaster prevention theory, we analyzed the adaptability of commonly used ecological slope protection types. We further integrated the solidifying, protective, permeable, filtration, and flexible advantages of various slope protection types aiming to address the current challenges faced by hard slope protection in the Kaifeng segment of irrigation channel diverted from the Yellow River. In consideration of the characteristics of sandy soil and the local conditions, we propose a method of ecological slope protection by using prefabricated PET net bag box suitable for areas above the normal water level in irrigation area. To assess the feasibility of this approach, we design four test conditions and conduct performance comparisons to verify the effectiveness of the PET mesh bag box for ecological slope protection. Test results demonstrate that the shear strength of the soil mass using the PET mesh bag box is significantly enhanced compared to the original ecological slope protection, particularly the cohesion of the soil mass, which is enhanced by approximately 110%. Additionally, the PET mesh bag box exhibits notable advantages in terms of soil drainage, construction convenience, engineering cost, and ecological environmental protection when compared to concrete, slurry masonry, and six-edge bricks. These findings provide valuable insights for similar projects and contribute to the ecological protection and high-quality development of the Yellow River basin.