NOVELTY - Preparation of microbial fertilizer involves activating Klebsiella pneumoniae, shaking, inoculating, and fermenting; activating Bacillus licheniformis, Bacillus amyloliquefaciens, Delftia tsuruhatensis, and Paenibacillus polymyxa, shaking, inoculating, shaking, and fermenting; mixing fermentation broth; and mixing rapeseed and soybean cake, adding nitrogen, phosphate and potassium fertilizer, organic material, and mixed fermentation broth, fermenting, adding humic acid and grass peat, granulating, checking, and packing.    USE - Method for preparing microbial fertilizer used for promoting rice seedling root growth (claimed).    ADVANTAGE - The fertilizer enhances resistance to adverse environmental impact on rice seedling root growth and promotes strong roots and seedlings.    DETAILED DESCRIPTION - Preparation of microbial fertilizer comprises (A) activating Klebsiella pneumoniae in Luria-Bertani (LB) solid culture medium with 10 mL peptone beef extract, shaking at 180 revolutions/minute (rpm) and at 30 degrees C for 20 hours, inoculating with 400 mL peptone beef extract, shaking at 180 rpm and at 30 degrees C for 20 hours, fermenting with fermentation culture medium at 100% oxygen and at 30 degrees C for 48 hours, where stirring speed is 350 rpm and pH is 6.8-7.2, and sampling to detect viable spore concentration to greater than or equal to 1.0x 108 CFU/mL; (B) activating Bacillus licheniformis, Bacillus amyloliquefaciens, Delftia tsuruhatensis, and Paenibacillus polymyxa in 10 mL LB liquid culture medium, shaking at 180 rpm and at 30 degrees C for 20 hours, inoculating with 400 mL peptone beef extract, shaking at 180 rpm and at 30 degrees C for 20 hours, fermenting with fermentation culture medium at 100% oxygen and 30 degrees C for 48 hours, where stirring speed is 350 rpm and pH is 6.8-7.2, and sampling to detect viable spore concentration to greater than or equal to 1.0x 108 CFU/mL; (C) mixing fermentation broth of Klebsiella pneumoniae, Bacillus licheniformis, Bacillus amyloliquefaciens, Delftia tsuruhatensis, and Paenibacillus polymyxa at volume ratio of 1.5:1:1:1:0.5 to prepare mixed fermentation; and (D) mixing rapeseed cake and soybean cake at weight ratio of 1:1 as organic material, adding nitrogen, phosphate and potassium fertilizer as compost, where weight ratio of nitrogen, phosphate and potassium is 3:1:1, mixing with organic material and mixed fermentation broth, fermenting for 1 week, adding humic acid and grass peat, mixing, roll extrusion granulating, detecting viable spore microorganism, organic matter and water content, where live spore content is more than 1.0x 108 CFU/mL, organic matter content is more than 60%, and water content is 8-10%, checking, and packing.