As a functional material, high-purity single-walled carbon nanotubes are widely used in basic science and nanotechnology, such as mechanics, thermology, electricity, etc. Single-walled carbon nanotubes prepared by arc discharge method have fewer defects and are more suitable for mechanical and electrical applications; therefore, arc discharge method was adopted to prepare single-walled carbon nanotubes in this paper. Firstly, single-walled carbon nanotubes were prepared by dc arc discharge. Then, single-walled carbon nanotubes were purified by physical and chemical synthesis, after burning, acidification and selective dissolution in organic solvent, single-wall carbon nanotubes with high purity were obtained. Single-walled carbon nanotubes which purified before and after was investigated by Uv-visible-near-infrared spectroscopy, resonance Raman spectroscopy and high-resolution transmission electron microscopy.