The invention provides plant culture soil. The plant culture soil comprises, by weight, 20-36 parts of chicken manure, 10-48 parts of pig manure, 100-300 parts of potassium nitrate, 20-120 parts of fibrous bodies, 50-88 parts of calcium chloride, 46-97 parts of magnesium sulfate, 44-118 parts of monopotassium phosphate, 28-46 parts of ferric salt, 8-10 parts of decavitamin, 250-350 parts of agar, 2-5 parts of beer paste, 0.1-1 part of Chinese photinia leaf, 2-6 parts of water-retaining agents, 90-110 parts of potatoes, 40-60 parts of carbon powder and 11-22 parts of bean pulp. The invention further provides a processing method of the culture soil. The plant culture soil has good water and fertilizer retaining performance and high water and air permeability, the pH value of the culture soil can be stabilized, and a certain inhibition effect on reproduction of pathogenic bacteria is achieved; the processing method of the culture soil is simple, and industrialized production is easily realized.