The invention relates to the field of lithium ion battery anode materials, and in particular to a method for preparing a three-dimensional graded porous copper-zinc composite current collector. The preparation method comprises the following steps: 1) adsorbing a copper-containing waste liquid by wood powders, separating filter residues and a filtrate by filtration; 2) mixing mixed ambary powders,PMMA powders and the filter residues, and performing electrophoretic deposition at constant voltage, heat preservation and drying to obtain a template; 3) plating the template with copper and placingthe template in a special atmosphere for calcination for a period of time, stilly placing the template in an organic liquid for a period of time, and obtaining a three-dimensional graded porous coppersubstrate by washing and drying; and 4) putting the three-dimensional graded porous copper substrate in a galvanizing liquid, performing pulse plating to obtain the three-dimensional graded porous copper-zinc composite current collector. The method can obtain a graded porous template by doping PMMA, ambary powders and wood powders of different particle diameters, can provide a large space for deposition of lithium metal, can provide a large specific surface area, reduces local current density, and inhibits the accumulation of lithium dendrites during growth.