Diabetes is a metabolic disease with chronically increased blood sugar levels, which has a serious impact on human health. Long-term hyperglycemia may lead to obesity and hypertension. Currently, drugs used clinically to treat diabetes, such as sitagliptin and linagliptin, have problems such as great toxic and side effects. The development of high-efficiency and safe natural hypoglycemic active substances has become a current research hotspot. Dipeptidyl peptidase-Ⅳ inhibitory peptides are a class of biologically active peptides that can reduce blood sugar by inhibiting the activity of DPP-Ⅳ. DPP-Ⅳ inhibitory peptides derived from natural foods have the advantages of high safety, small side effects, long-term use, etc., and can be used in hypoglycemic functional foods. The abundant marine biological resources are an important source for the preparation of DPP-Ⅳ inhibitory peptides. The source, separation and purification, structural identification and functional activity evaluation of DPP-Ⅳ inhibitory peptides from marine biological protein sources at home and abroad were reviewed, and recommendations were proposed for the further development and application, aiming to develop DPP-Ⅳ inhibitory peptide functional foods for reference.