The invention discloses nutritional soil for flowers and plants and a preparation method therefor and relates to the technical field of cultivation of the flowers and plants. The nutritional soil for the flowers and plants contains the ingredients in parts by mass: 5-10 parts of leaf mold, 20-30 parts of field soil, 3-5 parts of chicken manure, 2-3 parts of sawdust, 4-8 parts of plant nutritional agent, 9-12 parts of zeolite, 7-15 parts of maifanite, 10-12 parts of peat, 3-5 parts of decay ooze, 2-5 parts of ferrous sulfate, 7-11 parts of urea water and 5-6 parts of potassium dihydrogen phosphate water. By adopting the technical scheme of the invention, the preparation steps are reasonable, the operation is facilitated, the nutrition matching is scientific and reasonable, the cost is low, the survival rate of plant planting can be effectively increased, and the nutritional soil is environmentally friendly, sanitary, dry, crisp, air-permeable, non-toxic, odorless, bactericidal and antibacterial and is not prone to hardening.