The invention relates to a method for preparing a standard multi-element aluminum alloy sample. The method comprises the steps of proportioning materials, melting, casting, homogenization processing, extruding and post-processing, and is characterized in that the standard sample contains the following 20 chemical elements in pure aluminum: Si, Fe, Cu, Mg, Mn, Zn, Sn, Pb, Ni, Ti, Cr, Sr, Ca, V, Ga, Zr, Cd, Be, B and P. The standard sample is manufactured sequentially through proportioning materials, melting, casting, homogenization processing, extruding and post-processing, and finally, standard samples are prepared according to the requirements for the standard samples. By adopting the preparation method, the multi-element aluminum alloy sample with uniform composition and good stability can be obtained.