The present invention relates to a nanometer carbon tube technology. In order to raise the purification efficiency of multiple-wall nanometer carbon tube and simplify the operation, the present invention provides a kind of method of purifying multiple-wall nanometer carbon tube. The method includes the following steps: supersonic vibration, oxidation in the air, acid pickling and rinsing with deionized water to obtain pure multiple-wall nanometer carbon tube. The method features that it also includes the steps of boiling at 100 deg.C for 10-50 hr and bromization in bromine water of 3-10% concentration at 50-100 deg.C for 2-10 hr.