Plants are vulnerable to various abiotic stresses in the natural growing environment, among which salt stress can seriously affect plant growth, development and yield. Protein families containing trimeric tetrapeptide repeat sequences have a crucial function in plant resilience to non-living factors and participate in multiple aspects of plant growth and development. For this investigation, we acquired the apple MdTPR16 gene. The research demonstrated that ectopic expression of MdTPR16 in Arabidopsis resulted in increased resistance to salt stress. This was observed by a drop in malondialdehyde (MDA) levels and a reduction in the buildup of reactive oxygen species (ROS) under salt stress conditions. Meanwhile, apple calli, apple seedlings and apple rooting seedlings overexpressing MdTPR16 showed reduced sensitivity to salt stress. The results indicate that MdTPR16 has a critical positive regulatory function under salt stress, which may lay the foundation for a deeper understanding of the molecular pathways of salt tolerance in apple.