The present invention improves the hydrolysis reaction rate and yield by using the acid, alkali hydrolysis step and the half-solvent zeolite crystallization step to improve process cost reduction, operation time reduction, productivity and price competitiveness, To facilitate the commercialization of the medicinal plant cosmetics, and by neutralizing the acid hydrolysis reaction product and the alkaline hydrolysis reaction product by using hydrolyzate mixing and neutralization steps to terminate the reaction of the respective reaction products, The amount of the acidic aqueous solution to be used as a catalyst in the acid hydrolysis step is adjusted to 1.2: 1 or more by the addition amount of the aqueous alkali solution used as the catalyst in the alkaline hydrolysis step, 1, it is possible to obtain a separate acidity in the hydrolyzate mixing and neutralization steps Since it is not necessary to add a controlling agent, it is possible to increase the efficiency of the process. In addition, it is possible to reduce the amount of the cosmetic and reduce the fine powder by the micro-pulverization technique using an anti-To a process for purifying a complex polysaccharide derived from a medicinal plant by acid hydrolysis, alkaline hydrolysis, and zeolite crystallization, which reduces process operation cost and energy consumption.To this end, the present invention provides a method for preparing a medicinal crop, comprising: preparing a raw material comprising a medicinal crop by drying and pulverizing the raw material An acid hydrolysis step in which a part of the medicinal crop material compounded in the raw material preparation step is subjected to acid hydrolysis at 80C or higher and 100C or lower for not less than 1 hour and not more than 3 hours by introducing an acidic aqueous solution containing strong acid and weak acid Alkali hydrolysis in which alkaline hydrolysis is carried out at 80C or higher and 100C or lower for not less than 1 hour and not more than 3
