Abstract: In response to the challenge of utilising Yellow River sediment resources, artificial slope protection engineering techniques using vegetation substrates were employed to restore the ecology of coastal urban mine tailings ponds, with the aim of improving the water retention properties of vegetation substrates based on Yellow River sediment. Yellow River sediment was used to replace the natural soil, ordinary silicate cement was used as the main binder material, and different contents of straw fibre were added to prepare ecological substrate on this basis, and the cumulative water loss, water retention capacity, pore volume, porosity characteristics and different pore types were determined and tested, and microscopic using scanning electron microscope and X-ray diffractometer were detection, and systematically analysed the effects of different cement and straw fibre contents on the water retention of the vegetation substrate and the mechanism of action. The results showed that: at 6% straw fibre addition and 6% cement addition ratio, the vegetation substrate based on Yellow River sediment appeared to have a maximum water retention of 66.1 g, 75.94% soil capillary porosity, and 79.68% total porosity, which significantly improved the water retention of the vegetation substrate. It is recommended to carry out sandy soil improvement and ecological restoration works using the mass ratio (sediment∶amendment of habitat material∶organic fertilizer∶straw fibre∶cement = 100∶6∶6∶6∶6), and the results are suitable for ecological restoration of slopes with shortage of soil and water resources. The water retention mechanism of straw fibre and cement on vegetation substrate mainly includes the physical filling effect of straw fibre, the respective chemical cementing effect of both and the synergistic effect of cement and straw fibre. The vegetation substrate based on Yellow River sediment has the characteristics of low manufacturing cost and environmental friendliness, and it can realise the resourceful and efficient use of Yellow River sediment, and the research results can be promoted to other lake and reservoir areas involving dredging in the river basin, which is important for the ecological protection and restoration of the basin.