Organic-inorganic composite passivator for cadmium contaminated soil and using method of composite passivator

The invention provides an organic-inorganic composite passivator for cadmium contaminated soil and a using method of the composite passivator. The composite passivator is formed by mixing of silkwormexcrement biomass charcoal and an iron-containing reagent, wherein the usage amount of the silkworm excrement biomass charcoal is 1% of the mass of the cadmium contaminated soil to be restored and theusage amount of the iron-containing reagent is 0.2% of the mass of the cadmium contaminated soil to be restored; and when the silkworm excrement biomass charcoal and the iron-containing reagent are used, the silkworm excrement biomass charcoal and the iron-containing reagent are added into the cadmium contaminated soil to be restored, mixing is performed, water is added for maintenance, and the water content of the soil is controlled to be 40%. According to the organic-inorganic composite passivator for the cadmium contaminated soil provided by the invention, the adopted reagent raw materialshave wide sources and low