The fabrication of functional surface covered with novel nanostructures for various applications has attracted much attention in recent years. A large area of randomly distributed nanospikes can be induced on the surface of aluminum (Al) film in sucrose solution by using femtosecond (fs) laser, and the distribution density of nanospikes varies with laser pulse energy and mass ratio for sucrose to water. After modification with polydimethylsiloxane (PDMS), the Al film covered with nanospikes exhibits the characteristics of tunable wettability, underwater superoleophilicity (~0°), superhydrophobicity (~155.3°), high water adhesion and environmental stability. Further, an oil-water separation filter was prepared by using fs laser direct writing (LDW) on one side of the Al film in air and then inducing nanospikes in sucrose solution as well as PDMS modification on the other side. After the above treatment, the filter has low water adhesion similar to “lotus effect” and can be used for highly efficient (99.61% ~ 99.63%) and recyclable oil-water separation. In addition, the filter exposed to air for more than 7 months still remains high oil-water separation efficiency (99.46% ~ 99.57%), showing strongly environmental stability. This functional filter fabricated by fs laser can be applied in the separation process of chemical products, biomedical device, and environmental protection fields.