As base stable NF membranes could be applied to the treatment of strong-alkalinity wastewater without neutralization as the pretreatment, there is no additional solid waste produced. The mercerization wastewater being treated with such membranes, the recovery rates for alkali liquor and alkali could achieved to 95% and 90%, respectively, and the permeate could be sent back to the production process for reuse. Hence, the clean production was realized, and the environmental pollution was reduced.