The invention discloses a liquid bacterial agent for rooting, which comprises the following raw materials by weight parts: 20-80 parts of concentrated amino acid fermented liquid, 15-30 parts of urea, 5-20 parts of potassium fulvic acid, 10-20 parts of alginic acid, 5-15 parts of chitosan, 10-30 parts of bacillus subtilis, 5-20 parts of Alpha-pimacol, 10-35 parts of sodium nitrophenolate, 1-4 parts of indole butyric acid potassium, 5-15 parts of 5-nitrate and 10-20 parts of calcium nitrate. According to the invention, the liquid bacterial agent contains various high-activity strains including bacillus laterospor, bacillus licheniformis, bacillus subtilis and the like and dozens of high-purity nutritional ingredients. The liquid bacterial agent has super strong activity, and can quickly reach nutrient deficiency parts and bacteria infection parts of crops after being used so as to quickly complement the deficient elements, and can split mycelium and spore and remove soil-borne diseases so as to allow the crops to be quickly back to health. The liquid bacterial agent has the advantages of good water solubility, strong absorption ability, non-public hazard, no residue and no volatility after being used, and can not cause poison damage for the crops in the greenhouse.