The invention provides a method for preparing grafted hydroxypropyl oligochitosan procyanidine freeze-dried powder, and belongs to the technical field of functional additives for daily use chemicals. Oligochitosan and procyanidine are used as raw materials, a multifunctional new product which has activities of ultraviolet resistance, radiation resistance, ageing resistance, heavy metal chelating, whitening, moisturizing and the like, and further has an antibacterial property by steps of preparation of a hydroxypropyl oligochitosan solution, preparation of a grafted hydroxypropyl oligochitosan procyanidine solution, preparation of a grafted hydroxypropyl oligochitosan procyanidine desalted concentrated solution and preparation of the grafted hydroxypropyl oligochitosan procyanidine freeze-dried powder, and the yield counted by the procyanidine is 93-99%. The method is simple and convenient to operate; used production equipment is easily purchased; raw materials resources are utilized fully; the production cost is low; the method is convenient to popularize and use; and the product prepared by the method can be widely used in the daily use chemical field, such as surface coating or antibacterial and anti-radiation materials including skin care products, cosmetics such as lipsticks, food, health-care products and the like.