The invention discloses a method for preparing a carbon-nanotube-modified aluminum material from boride-coated single-walled carbon nanotubes. The method comprises the following steps of (1) preparing single-walled carbon nanotube dispersion; (2) adding a boride precursor, forming uniform boride layers on the surfaces of the carbon nanotubes by using a chemical coating method, performing filtering and heating after the reaction is finished, and performing treatment at 150 to 250 DEG C to obtain boride-coated single-walled carbon nanotube powder; (3) adding the boride-coated single-walled carbon nanotube powder into molten aluminum for uniform dispersion, and performing standing, casting, extrusion and subsequent heat treatment to obtain the carbon-nanotube-modified aluminum material. According to the method, the compatibility of the carbon nanotubes and the molten aluminum is effectively improved and a density difference between each carbon nanotube and the molten aluminum is effectively increased, and the degree of dispersion of the carbon nanotubes in the molten aluminum is improved; a modification enhancement function of the single-walled carbon nanotubes in an aluminum substrate is fully utilized, and the electrical conductivity and the mechanical strength of the aluminum material are greatly improved.