A novel high-flux sulfonated polyamide nanofiltration (NF) hollow fiber membrane was made from the mixed monomers of 2,2′-benzidinedisulfonic acid (BDSA) and piperazine (PIP). By optimizing the preparation parameters (TMC concentration, reaction time and BDSA/PIP mixing ratio), the optimized NF membrane possessed a pure water permeability (PWP) of 49.1 L m⁻² h⁻¹ and a Na₂SO₄ rejection of 95.5% under 4 bar. The molecular weight cut off (MWCO) of the BDSA/PIP NF membrane was about 400 Da. Furthermore, in a long-term antifouling test with 0.3 g L⁻¹ bovine serum albumin (BSA) solution, the total flux decline rate (FDR) and the flux recovery ratio (FRR) of the membrane were 16.7% and 85.7% respectively, which indicated the good antifouling properties and application prospects of the TFC NF membrane.