An optimized cleaning strategy of a thin-film composite membrane functionalized with zwitterionic poly(sulfobetaine methacrylate) brushes (TFC-PSBMA membrane) was investigated for a long-term forward osmosis (FO) treatment of polymer-flooding produced water (PFPW). Crude oil and anionic polyacrylamide (APAM) were used as the representative organic substances in the wastewater. The results showed that irreversible fouling was significantly aggravated by increasing the relative concentration of crude oil in the feed solution revealing it to be the major foulant. Then, five cleaning protocols were investigated such as deionized water washing, NaCl osmotic backwashing, chemical washing with acid, alkali, and surfactant cleaning, respectively. As the result, it was found that chemical cleaning with sodium dodecyl benzenesulfonate (SDBS) was the most effective method for removing foulants from the membrane surfaces. Meanwhile, PSBMA brushes grafted on the membrane exhibited excellent tolerance to the chemical stress caused by SDBS but not to NaOH.