The invention discloses a preparation method of bionic oil-water separation copper foam. A bionic natural plant leaf surface is hydrophobic and self-cleaning; an oxidation deposition method is used for preparing a double-layered graded super-hydrophobic surface with a pH (Potential of Hydrogen) responding bionic micro-nano scale; the method comprise: washing copper foam with diluted hydrochloric acid, acetone and distilled water to realize pre-treatment; immersing the copper foam into a reaction solution and carrying out oxidation deposition, so as to change shape characteristics of the surface of the copper foam, and form a bionic micro-nano scale double-layered graded structure on the surface of the copper foam; after finishing the oxidation deposition, immersing a copper net with the bionic micro-nano scale double-layered graded structure into a modification solution, so that a low-surface-energy film is formed on the surface of the copper net; finally, enabling the surface of the copper net to have a pH responding super-hydrophobic property. The preparation method has the advantages of simplicity in operation, controllable experiment parameters and low cost, and can be used for manufacturing an oil-water separation material; the bionic oil-water separation copper foam has a certain responding property on the acid-base property of a solution, can be used for carrying out acid-alkali controllable oil-water separation, and has good mechanical stability and repeated utilization property.