Permeable reactive barrier and method for remediation of underground water pollution of landfill and polluted site

The invention provides a permeable reactive barrier and method for remediation of underground water pollution of a landfill and a polluted site, wherein the reactive barrier comprises at least one reactive barrier module, the reactive barrier module comprises a module framework, the two ends of the module framework are both provided with filter screens, and a quartz sand filling material layer, a coal ash filling material layer, an activated carbon filling material layer, a reduced iron powder filling material layer, an iron modified rutile filling material layer, an activated aluminum oxide filling material layer and a titanium dioxide filling material layer are sequentially filled between the two filter screens. Underground water polluted by arsenic, cadmium, lead and the like is repaired by arranging the permeable reactive barrier, the pollutant treatment efficiency can be improved, the treatment cost can be reduced, secondary pollution is effectively avoided, the treatment process is clean and efficient,