Ceramic nanofiltration (NF) is a newly developed technology for municipal sewage reclamation for drinking water production, agricultural and industrial utilisation, but organic fouling limits it to pilot-scale application. Herein, Fenton-based cleaning catalysed by FeOCl pre-coat was performed on ceramic NF membrane to clean persistent gel-like fouling. FeOCl pre-coating on ceramic NF membrane was conducted by pressure-driven filtration. Gel-like fouling was simulated by Ca-alginate. The compact fouling layer was proposed to impede the diffusion of H2O2; therefore, NaCl was introduced to perform Na-Ca ion exchange to relax the fouling layer and improve the mass transfer in Fenton-based cleaning. The cleaning efficiency of Fenton cleaning and NaCl treatment were evaluated individually, and their synergistic effect was determined by a mixture of NaCl/H2O2. In pre-coating, the iron loading could be controlled by permeate flux. Moreover, the iron loading on the membrane had a linear relationship with FeOCl dosage. The pre-coated FeOCl layer slightly decreased membrane permeability (by 4%), presumably because the porous FeOCl pre-coat provided abundant channels for water permeation. NaCl pre-treatment displayed high efficiency in the removal of the reversible fouling layer, which contributed to 50% of flux decline. The FeOCl pre-coat catalysed Fenton-based cleaning, which achieved a complete flux recovery in 1 hour. The addition of tert-butanol (an ∙OH scavenger) in Fenton-based cleaning system decreased the cleaning efficiency, which confirmed the participation of ∙OH in Fenton-based cleaning. No remarkable synergistic effect was observed between NaCl induced fouling layer swelling and Fenton oxidation. It was likely due to the effect of turbulent flush on improving the diffusion of H2O2 in Fenton-based cleaning, which surpassed the effect of fouling layer swelling induced by NaCl treatment.