The invention discloses a method for extracting pectin from shaddock peel, and belongs to the technical field of shaddock deep processing. The pectin with the purity reaching up to 98.3% to 98.7% is quickly prepared by taking shaddock white rind obtained after naringin extraction as a raw material through the steps of sulphurous acid solution preparation, stabilized shaddock peel mixed solution preparation, pectin extracting solution preparation, pectin separating solution preparation, pectin concentrated solution preparation, pectin filter cake preparation, pectin preparation and the like. According to the method, the pectin is extracted through sulphurous acid, therefore, degradation of acid on pectin molecules is eliminated, and corrosion of strong acid to production equipment is reduced; centrifugal separation is conducted on pectin filtrate through a disk centrifuge, separation liquid is concentrated through an ultrafiltration membrane, therefore, the pectin quality is obviously improved, and meanwhile energy consumption is reduced; the production equipment is conventional equipment, the production condition is easy to implement, operation is convenient, the method is suitable for industrialized production, and the product quality meets the market requirements. The pectin product produced through the method can be widely applied to the fields of food, cosmetics and the like.