Method for extracting and separating components in ramulus mori skin

The invention discloses a method for extracting and separating components in ramulus mori skin. The method comprises the following steps: decoloring waste liquor of pre-processed ramulus mori skin, which is subjected to two-time alkali digestion, and then concentrating the waste liquor; adjusting pH to 1.5-7.0, adding 95% ethanol at the volume ratio of 1:(0.8-4), and carrying out centrifugal separation, wherein precipitate is the mixture of pectin and hemicellulose, and supernate is a lignin-contained solution; distilling the supernate, adjusting the pH to be 3, and carrying out centrifugal separation, wherein the precipitate is lignin; dissolving the mixture of pectin and hemicellulose into water, adjusting pH to be 8.5, adding CaCl2 solution of which the concentration is 5%, carrying out centrifugal separation, washing the precipitate with deionized water, and washing with hydrochloric acid of which the volume ratio is 1: (30-40) and 95% ethanol to obtain the pectin; and after the supernate obtained by cent