Preparation method of environment-friendly plant-growing matrix

The invention discloses a preparation method of an environment-friendly plant-growing matrix. Polyurethane foam is used as a framework structure of the matrix; meanwhile, a water-retaining agent and nutrient substances needed by plant growth are added to prepare the environment-friendly plant-growing matrix for the plant growth; the strength, water permeability and porosity of the matrix can be adjusted according to a raw material ratio and syntactic foam. The matrix has the characteristics of light weight, degradability, slow release of nutrients, water preservation and the like, can be used in a plurality of environments and is used for engineering including roof greening, vertical greening, edge slope repairing, lawn planting, indoor greening and the like; the matrix can be used for effectively supporting the plant growth and has a good plant fixing effect; plants are not easy to fall; the matrix contains rich nutrient components and has a relatively high water-retaining capability; the soil-imitated spong