Soil remediation agent for reducing cadmium concentration of cultivated land as well as use method and application of soil remediation agent

The invention discloses a soil remediation agent for reducing the cadmium concentration of cultivated land, and belongs to the field of soil heavy metal pollution remediation. The soil remediation agent is prepared from the following components: 50 to 70 percent of wollastonite, 15 to 25 percent of magnesian clay, 10 to 15 percent of dolomite and 5 to 10 percent of quick lime. The content of cadmium in the rice can be remarkably reduced, meanwhile, the rice meets the national selenium enrichment standard, the economic added value is increased, and the method is economical, environmentally friendly, safe, efficient, capable of being practically applied to cadmium pollution regulation and remediation of selenium-enriched soil and wide in application prospect. In addition, the invention further discloses a using method of the soil remediation agent, and the using method comprises the steps of applying and scattering weight proportion, applying and scattering time and applying and scattering post-treatment. In ad