We have used molecular dynamics (MD) simulation to investigate the evaporation of the surface wall of multi-wall carbon nanotubes (MWCNTs) at high temperature，using the environment dependent interatomic potential (EDIP) to describe the C—C interaction in carbon nanotube. The simulation results show that the Stone-Wales defect in the surface wall of a multi-wall carbon nanotube vibrates violently，which causes C—C bond breaking and evaporation of atoms along the circumferential directions of the nanotube. The formation of Stone-Wales defect is attributed to the atomic thermal motion or tensile strain. Using the Lindemann index as a criterion，we found that the surface wall of MWCNT evaporates around 2290 K. Our simulation results agree very well with the observation of the surface wall evaporation of the MWCNT at 2000 ℃.