Effective separation of oil/water emulsion and removal of organic dyes are of critical importance for environmental protection. In this study, superhydrophobic polyacrylonitrile (PAN) nanofibrous membrane embedded Au nanoparticles (NPs) in cavity has been prepared through a facile electrospinning and subsequent surface-modification strategy. The as-prepared Au@ZIF-8@PAN-TD membrane exhibited a water contact angle (WCA: similar to 155.5 degrees), an oil contact angle in air (OCA: similar to 0 degrees) and a WCA under-oil (similar to 158 degrees). The composite membrane has demonstrated its ability to achieve efficient water/oil separation and in situ catalytic degradation of organic dye (e.g. 4-nitrophenol). The superhydrophobic Au@ZIF-8@PAN-TD membrane with a hierarchical porous structure would open an avenue for the purification of polluted oily water system.