NOVELTY - A nanometer composite material is composed of sheet-shaped graphite and rare earth complex containing rare earth element selected from lanthanum, cerium, praseodymium, neodymium, samarium, europium, erbium and yttrium, where chemical composition and mixture ratio of graphite and rare earth complex is such that rare earth complex is wrapped by oxidized graphite alkene layer to form sandwich structure of nanometer composite material.    USE - As one-dimensional nanometer composite material, useful for inhibiting and killing colon Bacillus, Staphylococcus aureus, Bacillus pumilus, Bacillus subtilis, Klebsiella pneumoniae, copper green Pseudomonas and Salmonella typhi (all claimed).    ADVANTAGE - The nanometer composite material can be formed by simple operation process at mild conditions, thus reduces environment pollution, is low cost, has good dispersibility, sandwich-like structure, and sterilizing activity for bacteria. In composite, graphene oxide and rare earth ternary complex shows synergistic effect, and has broad spectrum antibacterial activity against common bacterial strains. The one-dimensional nanometer composite material when used for inhibiting and killing colon Bacillus, Staphylococcus aureus, Bacillus pumilus, Bacillus subtilis, Klebsiella pneumoniae, copper green Pseudomonas and Salmonella typhi, results in inhibition diameter for all the test bacteria of (more than 10 mm, preferably more than 20 mm), minimum inhibitory concentration of not greater than 200 ppm, and minimum bactericidal concentration of not greater than 800 ppm. Thus has high efficiency for inhibiting and killing harmful bacteria. In nanometer complex, rare earth complex shows improved dissolving dispersibility, bioactivity, thermal stability, and at the same time reduced toxicity to normal cell, particularly to humans, which improves human health, living standard and quality of life. The graphene oxide/rare earth ternary complex nano-composite material structure has special sandwich structure, which improves rare earth complex dispersing solubility in common solvent. The process for forming nanometer composite material includes environment-friendly material solution system, and includes charge driving self assembly.    DETAILED DESCRIPTION - A nanometer composite material is composed of sheet-shaped graphite and rare earth complex of formula RE(L1)(L2)2, where chemical composition and mixture ratio of graphite and rare earth complex is such that rare earth complex is wrapped by oxidized graphite alkene layer to form sandwich structure of nanometer composite material.    RE=rare earth element selected from lanthanum, cerium, praseodymium, neodymium, samarium, europium, erbium or yttrium;    L1=sodium salicylate, sodium benzoate, or m-hydroxyl;    L2=8-hydroxy-quinoline.    An INDEPENDENT CLAIM is included for method for preparation of the one-dimensional nanometer composite material composed of sheet-shaped graphite and rare earth complex, involving: adding graphite oxide in water, performing ultrasonic treatment for 3-5 hours to obtain graphene oxide dispersion; under stirring, slowly dripping to aqueous solution of rare earth chloride, the oxidized graphene dispersion liquid, after finishing dripping continuously stirring mixture for 1 hour and standing overnight to obtain graphene oxide and rare earth chloride mixed solution A; preparing ethanol aqueous solution of ligands L1 and L2 by mixing evenly, slowly dripping graphene oxide and rare earth chloride mixed solution A in the mixed aqueous solution to obtain mixed solution B, where in mixed solution B concentration of oxidized graphite alkene is (0.015-0.09 wt.%), concentration of rare earth chloride is (0.041-0.045 mol/L), concentration of ligand L1 is (0.041-0.045 mol/L), and concentration of ligand L2 is (0.083-0.091 mol/L), mixing solution B by continuing stirring for 30 minutes, adding sodium hydroxide solution to adjust pH of mixture to 6.5-6.8, where solution is turbid, then continuing stirring for 2 hours, standing obtained product for aging and filtering, treating obtained powder with de-ionized water and absolute ethyl alcohol repeatedly for washing, filtering for several times, and vacuum drying.    DESCRIPTION OF DRAWING(S) - The figure shows electron microscope photographs of common Gram-negative bacterium Escherichia coli and Gram-positive bacterium Staphylococcus aureus on graphene oxide/rare earth ternary complex nanometer composite material and non-nanometer composite material.