The invention provides a de-coloring method of cotton. The de-coloring method comprises the specific steps: (1) loosening the cotton; stirring and scattering a pre-washing solution until the
moisture of the cotton reaches 40 percent to 60 percent, wherein a pre-washing agent is prepared from 10 to 20 parts of 30 percent
hydrochloric acid solution, 5 to 10 parts of 5 percent organic phosphonic acid solution, 5 to 10 parts of 8 percent
sodium chloride solution and 50 to 80 parts of water; (2) washing with an
enzyme: adding the pre-washed cotton into an
enzyme washing agent, wherein the
enzyme washing agent is prepared from 10 to 20 parts of mercerized proteinase, 10 to 20 parts of a non-ionic washing agent, 10 to 20 parts of a caustic soda flake and 80 to 100 parts of water; immersing at
room temperature for 2 to 3 hours; (3) after washing with water, adding into an
oxygen bleaching agent, wherein the
oxygen bleaching agent is prepared from 3 to 5 parts of an
oxygen bleaching stabilizer, 10 to 20 parts of
hydrogen peroxide and 80 to 100 parts of water; (4) washing with the water for a plurality of times and
drying. The de-coloring method of the cotton is short in period, high in efficiency and low in cost; the treated cotton has good whiteness, less
weight loss, small
strength loss and good hand feeling and is easy to spin and weave.