Abstract: Calcium is one of the essential macro-elements in the human body. The scientific calcium supplementation is greatly significant to maintaining life and health. The peptide-calcium chelates with good calcium binding capacity and high bioavailability have attracted more attention. This work reviews the binding sites, binding modes, and intermolecular forces between calcium and peptides in peptide-calcium chelates. Compared with free calcium, chelated calcium is more easily absorbed in the intestine according to the summarization of the calcium absorption pathways. Peptide-calcium chelates, as a new generation of calcium supplements, have a rich source of raw materials, high bioavailability, good economic value, and broad development prospects. Further research is needed on the safety, physicochemical stability, digestive stability, and Ca²⁺ release mechanism of peptide-calcium chelates after intestinal absorption. This paper aims to provide new insight into the development of novel calcium supplements.