The Bi2WO6/N-TiO2composite was synthesized hydrothermally, andcharacterized by using XRD, XRF, FE-SEM, EDX, FT-IR, BET, PL, and UV–VIS DRS analyses.The improvement in the catalytic activity of the prepared composite is related to lower recombination, and narrow bandgap.ThedegradationofAcid Black172 was examined undercontinuous conditions by using a tray photoreactor in which the catalyst was supported on the FTO through spin coating. The effect of independent factors such asinitial pH (5–9),contaminantto photocatalyst mass ratio (10–30 mg/g), andflow rate (1.5–4.5 ml/min) on the degradation efficiency was investigated. The results indicated that at the optimum conditions ofpH = 5,contaminantto photocatalyst = 10 mg/g,flow rate = 1.5 min/mL, textile color removal efficiency was81%,andTOC removal efficiency was 75%under visible light intensity = 20 w/m2. In addition, a decrease and an increase in degradation in the presence of mineral salts and more light intensity under optimum conditions, respectively. The degradation efficiency decreased slightly after several uses which confirmed the good performance and reusability of the catalysts.