The invention discloses a bioremediation method for alkaline soil. The method comprises the following step: a bioremediation agent is diluted with water by 500-1000 times and applied to the to-be-remediated alkaline soil according to the dose of 10-15 L per mu, wherein the bioremediation agent is mainly prepared from an organic nutrient solution obtained from fruit and vegetable waste by enzymolysis, contains Lactobacillus plantarum, Lactobacillus acidophilus, candida utilis and Bacillus mucilaginosus, has the viable count exceeding 108 cfu/mL, and contains an organic acid nutrient solution produced through fermentation. In conclusion, the method can improve the remediation effect and stability of the alkaline soil, increase soil nutrition, improve the micro-ecological environment of the soil, improve crop growth and prevent environmental contamination caused by a chemical process, and is an environment-friendly improvement method.