The invention discloses a microbial improvement method for soil of an abandoned land of a mine. The method comprises the following steps of step 1, soil stabilization and plant surface planting through bacillus subtillis, wherein antibiotics are generated, hormones stimulating the plant growth are secreted, and host microorganisms are trapped and killed; step 2, nitrogen fixation, wherein gaseousnitrogen in the atmosphere is fixed through nodule bacteria, brown nitrogen-fixing bacteria and frankiaceae for providing nitrogen nutrients for plants; step 3, phosphorus and potassium adding, wherein potassium, silicon and phosphorus in soil minerals are decomposed through bacillus mucilaginosus; step 4, phosphorus and potassium dissolving. The microbial improvement method for the soil of the abandoned land of the mine has the advantages that through multi-proportion addition of a microbial agent, the introduction of harmful microbes is controlled and cut off, beneficial microbes are cultivated, the soil is improved continuously through the action of the beneficial microbes, heavy metals are controlled, chelated and conditioned through the decomposition characteristics of the cultivatedmicrobes, the PH value of the soil is neutralized, soil ripening is accelerated to improve the soil, the self-purification action is strengthened, and natural circulation is accelerated to improve thehealthy growth of hyperaccumulators.