Peptidyl carrier protein (PCP) is a core module in non-ribosomal peptide synthetase (NRPS). According to the assembly mechanism, each module of NRPS contains at least one PCP domain. PCP plays a role in the delivery of amino acid residues and polypeptides in different catalytic domains, and it serves as a platform to transfer amino acid residues and polypeptides to other internal modification enzymes. This paper reviews the structure, function, interaction with other catalytic domains, and the reduction of recombinant module activity of PCP, aiming to provide a theoretical basis for the construction of recombinant NRPS modules.