The invention discloses a preparation process of a high-thermal-conductivity extruded aluminum alloy profile. The preparation process comprises the following steps of 1) extrusion, 2) refining, 3) extruding, and 4) effectiveness and the like. An online air cooling technology is adopted, the process of solid solution treatment is omitted, so that the production efficiency is improved; and optimization is carried out on various parameters, especially effective parameters in the preparation process so as to obtain an optimal scheme. According to the preparation process, the formula of the aluminum alloy is improved, the content of Mg and Si in the aluminum alloy component is reduced, Mg / Si ratio is controlled, so that the type of the alloy is in a slightly excess type of Si, and the harmful effect of V is eliminated by adding the boron adding element. On the premise of keeping the hardness, the conductivity of the product is improved. Through verification, the vickers hardness of the product can reach more than 11 Hw or above, the tensile strength is higher than 215 Mpa, the electric conductivity at 20 DEG C is higher than 56% IACS, and the heat conductivity coefficient can reach 220W / mK or above, and all technical parameters reach the world leading level.