Soil conditioner for preventing and controlling accumulation of heavy metals arsenic and zinc in cabbages

The invention relates to a soil conditioner for preventing and controlling accumulation of heavy metals arsenic and zinc in cabbages. The soil conditioner is a mixture of silkworm excrement, mulberry leaf residues, quicklime and a silicon-calcium fertilizer, wherein the ratio of all the components in percentage by weight is 1:2:2:1. A pretreatment method of the soil conditioner comprises the following steps: collecting the natural mixture of silkworm excrement, mulberry leaf residues and quicklime, stacking in a shady and cool rainproof place for 5-6 months, drying in air, crushing until the particle size is less than 2mm, and mixing according to the ratio. According to the method, the soil conditioner is used for improving the polluted soil which is used for planting the cabbages; after the cabbages are planted in the improved soil, the content of the arsenic and the zinc in the over-ground parts of the cabbages is reduced obviously so that the arsenic content of the cabbages is qualified, simultaneously the toxicity of arsenic and the zinc to the cabbages is alleviated, and the growth of the cabbages is greatly promoted, so high yield of the cabbages is realized.