Heavy metal cadmium contaminated soil remediation agent, preparation method and application thereof

The invention discloses a heavy metal cadmium contaminated soil remediation agent, a preparation method and application thereof. According to the invention, gasification slag is subjected to modification treatment and irradiation and roasting treatment, so that the pore structure of the gasification slag is dredged, the specific surface area of the gasification slag is remarkably increased, silicon-aluminum active groups of the gasification slag are activated, the adsorption performance of the gasification slag is remarkably improved, and heavy metal Cd can be effectively fixed; and root exudate with proper molecular weight, starch and other nutrients and functional components are loaded on the gasification slag structure while the structure is modified, so that the fertilizer efficiency of the gasification slag repairing agent is improved, the water retention capacity is enhanced, the soil repairing performance is enhanced in multiple directions, and the mining area heavy metal contaminated soil repairing ef