The invention discloses a nutrient conditioner for acidified soil in orchards, and a preparation method and applications thereof. The conditioner comprises the following components in portions by weight: 5-10 portions of fly ash, 5-10 portions of furnace slag, 50-70 portions of calcium cyanamide, 0.5-1.0 portion of urease inhibitor, 10-20 portions of light burning powder, 5-10 portions of common calcium magnesium potassium phosphate, 3-5 portions of zinc oxide and 5-8 portions of refined bentonite. The preparation method of the invention is simple, and the conditioner is suitable for conditioning acidified soil in most orchards such as apple orchards, pear orchards and the like and can enhance the utilization efficiency of fertilizers; the conditioner can also be used as a carrier for producing microbian soil conditioners or producing organic fertilizers by fermenting with organic substances to increase the population quantity of microorganisms beneficial to soil; and the conditioner can obviously enhance the fruit output, improve the fruit quality and strengthen the disease resistance.