Commonly, single-walled carbon nanotubes (SWCNTs) are catalytically grown from transition metal nanoparticles at a high temperature ranging from 700 to 1100 C, where metal catalysts are in liquid or partial liquid states due to nanometer size effect, along with the vapor-liquid-solid growth mechanism of CNTs.Transition metal catalysts show obvious advantage of high catalytic growth efficiency.However, the unstable morphology and fluctuating structure of metal catalysts make it difficult to realize structure controlled growth of SWCNTs, which is currently a focus and big challenge of CNT research.