Waste-utilizing planting substrate, preparation method thereof and forming method of substrate block

The invention discloses a waste-utilizing planting substrate, and belongs to the technical field of planting substrates. The composition specifically comprises the following components: waste sludge in a papermaking method reconstituted tobacco or straw pulping production process; waste tobacco leaves, tobacco stems, tobacco leaves, tobacco stems or tobacco residues generated in the tobacco processing and application process; casting waste sand generated in the production process; and straw grass pulping and papermaking waste black liquid. Compared with the prior art, the fertilizer provided by the invention completely utilizes wastes as raw materials, has low energy consumption and good water retention performance, contains natural fulvic acid biological organic humic acid fertilizer and a large amount of nitrogen, phosphorus, potassium, trace elements and other nutrients, is beneficial to plant growth, also contains nicotine, has insecticidal and desinsectization effective components, and has a good applica