A process for producing refined cotton with a high polymerization degree includes: a. selection of material; b. impurity removal; c. impregnation; d. pretreatment: compounding triethanolamine, sodium carbonate, copper sulfate and magnesium oxide in equal proportion to form a cooking compound adjuvant with a mass concentration of 0.2-0.5%, putting the cooking compound adjuvant into a spherical digester together with the cotton linter subjected to the impregnation treatment, heating to 70 C, stopping heating, and subjecting to idling pretreatment for 40-60 min; e. cooking; f. cooling of the spherical digester; g. formulating a chlorine dioxide bleaching stabilization solution; h. a first stage of bleaching; I. alkali treatment; J. a second stage of bleaching; K. dechlorination; and l. rolling and drying by baking.