The invention relates to a pulping bleaching assistant and a cold soaking pulping technique, in particular to an energy and water saving clean pulping technique without water emission. The pulping bleaching assistant of the invention is specialized in making by the materials with the following weight portion: 1 to 50 parts of alumina oxide, 1 to 30 parts of papermaking whitening agent, 1 to 50 parts of sodium silicate, and 1 to 20 parts of sodium nitrite. The invention is mainly used for the pulping bleaching of the cotton stalk, poplar wood, etc., and the cold soaking pulping technique includes the following technique steps: the pulping material is washed, cold soaking is carried out, the material is squeezed, the pulp is grinded and bleached in a first round, the pulp is squeezed, the pulp is grinded and bleached in a second round, heating and bleaching are carried out, and the pulp is washed. The invention based on the theory of the cold soaking pulping has the advantages of improving the whiteness of the cotton stalk and poplar wood paper pulp, saving the dosage of the hydrogen peroxide and alkali, reducing the pulping cost, saving the fee of the grey water treatment, and improving the water quality.