The invention provides a soil matrix for reclamation of a waste slag field, which comprises, by mass percentage, 40-75% of original soil, 10-50% of engineering waste, 3-8% of organic fertilizer, and 3-7% of pine needles, wherein Original soil: engineering waste = 1:1‑4:1. At the same time, the preparation method and application thereof are provided. The soil matrix for reclamation of the invention can effectively dispose of a large amount of waste residue in the waste residue field, promote the growth of plants, and improve the survival rate. The natural soil, engineering waste residue and pine needles in the matrix form a loose and porous soil structure, which is conducive to soil ventilation and water transmission, the formation of aggregates in the soil, and the survival and reproduction of microorganisms. Organic fertilizer can effectively improve soil fertility, improve the originally barren engineering waste and natural soil, provide nitrogen, phosphorus, potassium, organic matter and other nutrients required for plant growth and development, and can passivate heavy metals contained in urban sludge. , reduce the possible harm caused by heavy metals in soil. The main materials are widely available and inexpensive.