The invention relates to the technical field of preparation of a metal or alloy nanotube, in particular to a preparation method of a nickel or nickel alloy nanotube. The preparation method of the nickel or nickel alloy nanotube comprises the following steps: (1) performing a reaction on nickel salt solution or mixed metal salt solution comprising nickel salt and aqueous alkali to generate a precursor colloid; (2) processing the precursor colloid under the hydrothermal condition to obtain a nanowire; and (3) performing the catalytic reaction on the surface of the nanowire and catalyzing the performance of a reducing agent and nickel ions by taking the surface of the nanowire as an active point so as to form a tubular structure of nickel and nickel alloy. Compared with the prior art, the preparation method disclosed by the invention does not require a hard template; equipment required by the preparation method is simple; the preparation method can be used only by improving a common reactor and constant temperature equipment; and moreover, the process is simple and easy to operate and the cost is low.