The invention belongs to the technical field of greening walls, provides a succulent planting matrix and further provides a method for building a greening wall and the greening wall. The planting matrix is prepared from, by weight, 40-60 parts of organic matter, 40-60 parts of particular matter, 0.5-1 part of plant protection agent and 3-5 parts of slow release fertilizer. The method for building the greening wall includes the following steps that S1, multiple greening wall planting modules not provided with fixing strips and decorative frames are provided; S2, succulents are transplanted into a planting chamber; S3, the greening wall planting modules are fixed to a wall through hanging grooves and hanging pieces, and the greening wall is obtained through combination. The succulent planting matrix is loose and breathable, water drainage and retention effects are good, no hardening is likely to happen, no settling is likely to occur on a vertical face, certain fertility can be kept for a long time, and root rot is avoided.