The invention provides a manufacturing method of body lotion by taking Pullulan polysaccharide and sericin bioactive peptide as main raw materials. According to the method, the body lotion is manufactured by using the Pullulan polysaccharide and the sericin bioactive peptide which are taken as main components and other auxiliary components in a matching way. The manufacturing method comprises the following steps of: 1. carrying out alkaline solution eluting and primary hydrolysis on sericin proteins; 2. separating and concentrating sericin protein liquid; 3. carrying out ultrasonic auxiliary enzymolysis on the sericin proteins; 4. separating the sericin bioactive peptide; 5. dissolving the Pullulan polysaccharide; and 6. preparing the body lotion by taking the Pullulan polysaccharide and the sericin bioactive peptide as the main raw materials according to the components. The molecular weight of the sericin bioactive peptide formed by using hydrolysis is in a range of 5000-20000Da; the sericin bioactive peptide is more easily absorbed by the skin than macromolecular proteins; and the effect of the sericin bioactive peptide is far better than that of the traditional collagen. The raw materials of the sericin bioactive peptide are selected from cocoon shells abandoned during a silk industry; and a secondary resource is effectively utilized and the production cost is greatly reduced.