The invention relates to a method for coating a carbon nanotube with metal-doped zinc oxide nano-particles, which mainly comprises the following steps: an alkaline solution and a mixed acid are adopted to treat the carbon nanotube; and then zinc acetate and metal acetate are taken as raw materials, absolute ethyl alcohol is taken as a solvent, oxalic acid is taken as a complexing agent, and co-precipitation method and subsequent heat treatment are adopted to prepare the carbon nanotube coated by the metal-doped zinc oxide nano-particles. The method utilizes a simple method to functionalize the carbon nanotube, so that the carbon nanotube is coated evenly and compactly by the zinc oxide nano-particles can be realized, and the nano-particles obtained have the advantages of even particle size distribution, small particle size, simple preparation process, low cost, etc. The major characteristic of the method is that: a surfactant is non-essential for modifying the carbon nanotube. The composite powder obtained not only can be taken as a powder raw material for preparing high-performance carbon nanotube/metal-based and carbon nanotube/ceramic-based composite materials, but also can be applied to the fields of optical devices, spinning electron devices, gas sensors, and the like.