NOVELTY - Fertilizer and its preparation method, are claimed. The fertilizer contains Bacillus amyloliquefaciens, B.thuringiensis, B.subtilis, lactic acid bacteria, substrate, corn straw, peat, fly ash, mushroom residue, swelling pig manure, methyl synergistic phosphorus powder, synergistic ether powder, ethylene, urea, diammonium phosphate, potassium sulfate, Sapindus, edible amaranth, cortex meliae and Quisqualis.    USE - The fertilizer is useful for preventing and/or treating woodbine powdery mildew.    ADVANTAGE - The fertilizer is broad-spectrum in sterilization characteristics, environmentally-friendly and less in possibility of generating drug resistance by weeds, and has excellent weeding effect.    DETAILED DESCRIPTION - Fertilizer and its preparation method, are claimed. The fertilizer comprises 0.8-1 pts. wt. Bacillus amyloliquefaciens, 0.6-0.8 pts. wt. B.thuringiensis, 0.5-0.7 pts. wt. B.subtilis, 0.4-0.8 pts. wt. lactic acid bacteria, 1-3 pts. wt. substrate, 30-35 pts. wt. corn straw, 20-30 pts. wt. peat, 30-36 pts. wt. fly ash, 10-20 pts. wt. mushroom residue, 30-40 pts. wt. swelling pig manure, 2-4 pts. wt. methyl synergistic phosphorus powder, 1-3 pts. wt. synergistic ether powder, 0.4-0.6 pts. wt. ethylene, 12-16 pts. wt. urea, 10-12 pts. wt. diammonium phosphate, 6-8 pts. wt. potassium sulfate, 55-60 pts. wt. Sapindus, 10-20 pts. wt. edible amaranth, 10-30 pts. wt. cortex meliae, 15-25 pts. wt. Quisqualis, 1-15 pts. wt. Chinese gall, 5-15 pts. wt. pubescent holly, 5-10 pts. wt. radix sophorae flavescentis, 10-15 pts. wt. fructus ulmi, 5-15 pts. wt. camphor, 5-15 pts. wt. semen momordicae and 10-15 pts. wt. golden larch bark. An INDEPENDENT CLAIM is included for method for preparing the fertilizer, which involves (a) fermenting the above-mentioned microorganism, (b) processing crop straw other raw materials, (c) inoculating microorganism into the processed raw materials, and fermenting mixture, (d) preparing plant extract, (e) mixing urea, diammonium phosphate and potassium sulfate with plant extract to obtain mixed fertilizer, (f) adding fermented mixture of step (c) to the mixed fertilizer, and (g) drying mixture, crushing and packaging to obtain finished product.