New technology of waste liquor from papermaking was provided by researching the treatment of waste water from pulping plant. The new technology incorporates evaporation and spray drying to the treating system of waste liquor. The technology of combining evaporation and spray drying was studied, practiced and concluded. Its economic analysis was also done. It was proved that not only zero discharge of extracted waste liquor could be realized, but also the lignin products were obtained by using this new technology.