The present invention provides a method for processing plant raw materials; in the present invention, the raw materials are pulverized, extracted with hot water, sieved to remove impurities, and then added with a specific proportion of n-butanol or isobutanol, oxidants and other additives, The cooking reaction, through the mutual cooperation of pretreatment conditions, solvent addition amount, oxidant addition amount, other additive addition amount and cooking conditions, synergizes, facilitates the penetration of reagents, fully separates raw material components, and basically retains active groups , remarkably improve the cooking efficiency and product yield, so that the product performance is better, the invention has a simple process, can realize industrialized large-scale production, can bring good economic benefits to enterprises, and has broad prospects.