Abstract: The massive generation of industrial oily wastewater and the frequent occurrence of oil spills have caused efficient treatment of oily wastewater to emerge as a global challenge. A superhydrophilic/ underwater superoleophobic stainless mesh (PDA-HNTs/SSM) was conveniently fabricated by in-situ immersion of polydopamine (PDA) and halloysite nanotubes (HNTs) and used for oil-water spearation. The surface morphology, chemical composition and wettability of the modified SSM were analyzed by SEM, EDS, FTIR, XRD, XPS and contact Angle instrument. The results showed that the wettability and surface micro-nano hierarchical structure of PDA-HNTs/SSM can be controlled by immersion times of PDA-HNTs. PDA-HNTs/SSM obtained by immersion for 10 times had the best wetting performance, the contact angle underwater of dichloromethane was 157°, and the sliding Angle is less than 5°. Dimetylbenzene, cyclohexane, n-hexane, petroleum ether and dichloromethane were used for oil-water separation test. The separation efficiency of PDA-HNTs/SSM was more than 99%, and still maintained above 95.5% after 50 cycles. Moreover, after standing in 1 mol/L HCl, NaOH and NaCl solution for 7 days or rubbing with sandpaper for 10 m, PDA-HNTs/SSM still maintained stable underwater superhydrophobility and good oil-water separation ability.