<p>To enhance the hydraulic properties of vegetation concrete while reducing cement usage and maintaining the long-term stability of vegetated slopes, this study proposes the incorporation of guar gum as a modifier for vegetation concrete. Through a series of direct shear tests, moisture stability tests, permeability tests, scanning electron microscopy, and pH tests, this research compares and examines the effects of varying concentrations of guar gum and cement on the moisture stability and permeability of vegetation concrete. The results demonstrate that the inclusion of guar gum significantly improves the moisture stability of vegetation concrete and reduces its permeability. Specifically, with a cement content below 4%, an increase in guar gum content leads to enhancements in the shear strength of the specimens, with cohesion and friction angle increasing by up to 32.30% and 6.63%, respectively. The moisture stability coefficient initially rises and then declines, with optimal stability observed at a guar gum content of 1.0%. Furthermore, guar gum-modified vegetation concrete exhibits reduced permeability and performs better in terms of alkalinity reduction during testing. Microscopic structural features demonstrate that guar gum not only binds soil particles but also fills pore spaces, leading to a comprehensive enhancement in the mechanical and hydraulic performance of vegetation concrete, which exhibits a good slope protection effect and application prospects.</p>