Preparation method for pulp

The invention provides a preparation method for pulp. The preparation method comprises the following steps: selection of plant raw materials; material preparation; and cooking. A cooking reagent used in the step of cooking comprises a cooking reagent used for alkali-process cooking, hydrogen peroxide and auxiliary agents; and the auxiliary agents are composed of modified glucose oxidase, at least one modified fatty alcohol polyoxyethylene ether and an acrylamide copolymer, wherein the usage amount of the modified glucose oxidase is 0.5 to 3% of the weight of absolute dry raw materials, the usage amount of the modified fatty alcohol polyoxyethylene ether is 0.5 to 5% of the weight of the absolute dry raw materials, and the usage amount of the acrylamide copolymer is 0.5 to 3% of the weight of the absolute dry raw materials. The method is implemented at a low temperature; damage to cellulose is small; the cooked pulp has high whiteness; and black liquor has low COD content and low chroma.