Abstract: Silver nanoparticles (AgNPs) are widely used in the field of biomedicine. However, the synthesis of AgNPs by traditional physical and chemical methods has problems such as pollution, product toxicity, and time-consuming. Therefore, it is extremely important to explore the preparation of AgNPs. Silver nanoparticles (AgNPs) of sweet corncob polysaccharide (SCP-AgNPs) were successfully synthesized by green method using sweet corncob polysaccharide (SCP) as raw material and the reaction conditions were optimized. The generated AgNPs were characterized by transmission electron microscopy (TEM), X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy, and their antioxidant and anti-diabetic abilities in vitro were investigated. The results showed that the optimum reaction conditions of SCP-AgNPs were as follows: the concentration of silver nitrate in the solution was 0.75×10⁻³ mol/L, the pH was 10.0, and the reaction time was 80 min. The prepared SCP-AgNPs were spherical with an average particle size of 13.5 nm. The structure showed a face-centered cubic crystal structure, and Ag was determined to be Ag0 state. The functional groups of biomolecules in SCP-AgNPs were characterized. The results of in vitro experiments showed that the synthesized SCP-AgNPs had strong free radical scavenging effect. At the same time, SCP-AgNPs had a good inhibitory effect on the activity of α-glucosidase and α-amylase. SCP-AgNPs has a significant inhibitory effect on key enzymes of diabetes and has potential anti-diabetic activity. It is a nano-drug suitable for nano-biomedical applications and will be widely used in food processing, medicine and other fields in the future.