The invention discloses a super-hydrophobic super-oleophylic
nanofiber membrane used for oil-water mixture separation and a preparation method thereof. The preparation method comprises the following steps: dissolving biphenyltetracarboxylic dianhydride and p-phenylenediamine into N,N-
dimethyl formamide, and reacting for 12-24 hours at a temperature of -10 to -5 DEG C under a
nitrogen gas environment to synthesize a
polyamide acid solution; dissolving biphenyltetracarboxylic dianhydride and p-phenylenediamine into N,N-
dimethyl formamide, and reacting for 12-24 hours at a temperature of -10 to -5 DEG C under a
nitrogen gas environment to synthesize a
polyamide acid solution; dissolving biphenyltetracarboxylic dianhydride and p-phenylenediamine into N,N-
dimethyl formamide, and reacting for 12-24 hours at a temperature of -10 to -5 DEG C under a
nitrogen gas environment to synthesize a
polyamide acid solution; preparing the polyamide acid solution into a polyamide acid
nanofiber membrane,and heating for performing imidization on the polyamide acid
nanofiber membrane to obtain a
polyimide nanofiber membrane; and sequentially putting the
polyimide nanofiber membrane into a
polydimethylsiloxane solution and
carbon dioxide nano-
particle suspension liquid to soak, and taking out to dry. The obtained PDMS-SNPs / PI membrane can normally work under bad conditions such as a high-temperaturecondition, a strong acid condition and a strong alkaline condition; and meanwhile, the nano structure with a
rough surface improves oil-water separating performance, has separating efficiency of 98%or above, and can be circularly and repeatedly used.