<p>A systematic evaluation of eight natural cross-linking agents was conducted to establish a rational selection strategy for tailoring the properties of pea starch/polyvinyl alcohol (SPVA) composite films. FTIR and XRD analyses confirmed successful interactions between all crosslinkers and the SPVA matrix, yielding transparent films with good compatibility and enhanced structural stability. Key findings revealed a distinct trade-off between mechanical strength and flexibility: proteinaceous agents (soy protein isolate, chitosan) significantly improved tensile strength and hydrophobicity but reduced elasticity, while organic acids (citric, malic, tartaric acids) acted as plasticizing crosslinkers to enhance flexibility. For barrier performance, citric acid provided superior moisture resistance, and malic acid achieved the lowest oxygen permeability. The composite films exhibited tailored functionalities for specific packaging needs, with good stability in aqueous environments. By elucidating distinctive structure-function relationships, this work provides a targeted reference for selecting natural cross-linking agents to fabricate high-performance bio-based films, supporting their application as sustainable alternatives in the food packaging industry.</p> Graphical abstract <p></p>