The invention provides a biological remediation method for soil polluted by
cadmium,
zinc, lead and
copper ions. The biological remediation method is realized by the following technical scheme comprising the following steps: (1) selecting the soil to be remediated, polluted by
heavy metals, manually removing weeds and shrubs, applying enough decomposed organic agricultural foreign fertilizers in the end of autumn and the beginning of winter, deeply ploughing to enable the soil to be weathered, freezing
overwintering pests for death, ploughing a land thoroughly and crushing the soil by a rake; (2) after the soil is unfrozen in the spring, when the average temperature reaches more than 10 DEG C,
transplanting woody and fast-growing trees, namely bamboo willows with the heavy-
metal enriching capability; (3) after the
transplanting is finished, when the temperature reaches more than 15 DEG C, implementing the
earthworm remediating process, and then collecting earthworms; and (4) after the first-time collection of the earthworms in the
earthworm remediating process, planting
elsholtzia splendens and alfred stonecrop and then wholly removing the
elsholtzia splendens plants and the alfred stonecrop plants with roots, and in the spring next year, reintroducing the earthworms, the
elsholtzia splendens and the alfred stonecrop into the land for remediation again, wherein the whole remediation process lasts for 20 months totally.