The invention relates to a multifunctional light inorganic culturing substrate for greening. The multifunctional light inorganic culturing substrate mainly comprises the following components in percentage by volume: 45-55 percent of pearl stone, 30-40 percent of thoroughly-decomposed wood dust, 8-13 percent of medical stone and 2-7 percent of pumice serving as media; meanwhile, a nutritional layer consisting of 8-20 g/m<3> of inorganic fertilizer nitrification inhibitor, 150-280 g/m<3> of agricultural potassium sulfate, 100-400 g/m<3> of diammonium phosphate, 200-500 g/m<3> of urea, 10-30 g/m<3> of agricultural copper sulfate, 15-40 g/m<3> of manganese sulfate, 10-30 g/m<3> of agricultural zinc sulfate, 10-30 g/m<3> of agricultural ferrous sulfate, 5-15 g/m<3> of boric acid, 200-300 g/m<3> of plant water retention agent and 0.19-0.38 g/m<3> of microbial insecticide is added; and a draining layer consists of water accumulating and draining plates for greening. The multifunctional light inorganic culturing substrate has the excellent properties of high particle strength, stable performance, durability, light weight, cleanliness, multiple functions, complete drainage, water retention, fertilizer retention, environmental friendliness, high efficiency, easiness and convenience for constructing, suitability for plant growth, and the like. The multifunctional light inorganic culturing substrate with a special agglomerate porous structure is better suitable for root system development of plants, and has a good fixing effect.