Abstract: Metal-organic framework (MOF) material is expected to improve the water flux and antifouling property of forward osmosis (FO) membrane, and improves its separation performance to emulsified oil wastewater. In order to introduce MOF into FO membrane, poly(p-chloromethyl styrene)-polyvinylidene fluoride (PCMS-PVDF) blend substrate was prepared by phase inversion method. The chloromethyl group (—CH₂Cl) in the substrate reacted with secondary or tertiary amine in 2-methylimidazole (Hmim), and then reacted with zinc nitrate (Zn(NO₃)₂). The antifouling FO membrane was prepared by in-situ growth of metal-organic zeolite imidazolium ester skeleton-8 (ZIF-8) and interfacial polymerization. The surface chemical structures and hydrophilic/hydrophobic property of substrate membrane and FO membrane were characterized by SEM, XPS, FTIR, contact angle analyzer and so on. The results show that ZIF-8 grows uniformly on the surface of PCMS-PVDF substrate, and the nanocrystals are cubic crystals with regular shape. Due to the presence of ZIF-8, the substrate surface is hydrophobic, but the new polyamide layer formed by interfacial polymerization makes the membrane surface hydrophilic again. The results show that the water flux of the FO membrane (PCMS-PVDF-FO) without ZIF-8 modification is only 12.4 L·m⁻²·h⁻¹, but the FO membrane (ZIF-8/PCMS-PVDF-FO) modified with ZIF-8 reach 20.7 L·m⁻²·h⁻¹ when using 1 mol/L NaCl as the drawing solution in FO mode. The separation experiment of emulsified oil simulated wastewater shows that the recovery ratio of pure water flux of FO membrane (ZIF-8/PCMS-PVDF-FO) is remained 89.9%, the total fouling ratio is 27.5% after running four cycles for pure water-emulsified oil separation. But under the same condition, the flux recovery rate of PCMS-PVDF-FO is only 66.9%, and the total fouling ratio increases to 66.2%. Based on the above, it can be seen that the FO composite membrane modified by in-situ growth of ZIF-8 exhibits excellent performance in emulsified oil wastewater separation.