The invention discloses a novel method for preparing load nano zero valent iron. The iron source is iron-containing compounds of Fe<2+> and Fe<3+>, such as ferric oleate, ferric hydroxide oxide, ferric chloride, ferric nitrate and the like; and the loads are carbon black, active carbon, kieselguhr, zeolite and other load materials. The method is characterized in that: the iron-containing compounds on the loads are reduced into nano zero valent iron under the atmosphere condition and under the reduction action of reducing agents, such as H2, CO, and reduction carbon (such as coke, reduction coal and the like). The preparation method is environment-friendly, and simple and is low in cost; the expensive reducing agents (such as NaBH4 and the like) are avoided, and organic pollutants (such as halogenated hydrocarbon, pesticide, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), inorganic negative ions (such as NO<3->), and heavy metal (such as Cr<6+>, As<3+>, As<5+>, Cu<2+>, Pb<2+>) and the like can be efficiently removed effectively.