Abstract: The underwater superoleophobic copper net was successfully prepared on copper mesh by one-step oxidation method. The contact angle of oil can reach 160° and the roll angle can reach 4°.The phase structure, surface morphology and infiltyation of the samples were characterized by XRD, TEM and contact angle measurement. Then, the formation mechanism, the influence factor of the oleophobicity and the application in the separation of oil/water were discussed. The experiment results showed that the micro-nanoscale structures obtained by oxidation method could increase the surface roughness of copper mesh. The concentration of oxidation liquid and the pore size of copper mesh had a significant effect on the oleophobicity, and the separation efficiency which could reach the value of 94% was affected by different water environment and oil/water ratio.