Abstract: Papaya (Carica papaya L.) is a typical climacteric tropical fruit characterized by rapid postharvest ripening and high susceptibility to softening, moisture loss, chilling injury, and pathogenic decay, which together severely constrain its storage, transport, and marketing. During postharvest ripening, elevated respiration and ethylene biosynthesis serve as the primary signals that initiate and coordinate ripening, driving subsequent changes in peel color, texture, and flavor. As ripening advances, chlorophyll degradation and carotenoid accumulation shift the pericarp from green to yellow; soluble sugars accumulate while organic acids decline, thereby increasing the sugar-acid ratio; and volatile compounds — including linalool, esters, and lactones—are progressively synthesized, collectively defining the sensory quality of the fruit. Concurrently, sustained depolymerization of cell wall polysaccharides (pectin, cellulose, and hemicellulose) leads to rapid pulp softening, whereas exposure to low temperature, together with perturbations in oxidative and energy metabolism, compromises membrane integrity, precipitating chilling injury and aberrant ripening while heightening disease susceptibility. Accumulating evidence indicates that these processes are not autonomous but are integrated through a regulatory network in which ethylene functions as a central hub, exhibiting extensive crosstalk with abscisic acid (ABA), auxin (IAA), jasmonic acid (JA), and salicylic acid (SA), together with Ca²⁺, and operating via transcriptional reprogramming, post-translational protein modification, and the coordinated metabolism of cell walls, pigments, sugars, acids, and aroma volatiles. Targeting these key nodes, diverse preservation strategies have been developed—low-temperature and cold-shock treatments, controlled and hypobaric atmosphere storage, ethylene management, coating film packaging, exogenous regulators, natural antimicrobials, biological control, and their combinations—that delay ripening, preserve cellular homeostasis, and reinforce disease resistance. Nevertheless, current preservation practices still face intrinsic limitations, including the difficulty of reconciling senescence retardation with normal ripening, low-temperature-induced chilling injury and flavor loss, and inadequate consistency of natural and biological agents; these limitations stem largely from an insufficient understanding of multi-signal synergistic mechanisms, genotype-dependent variation in storability, and the mechanistic basis of synergistic preservation. Future research should prioritize functional validation of key regulatory nodes, leverage multi-omics integration to dissect the coordination among ripening, quality formation, and stress tolerance, and engineer precise, green preservation systems adaptable to diverse cultivars and supply-chain conditions.