Polygoni Multiflori Radix Praeparata (PMRP), a processed root of Polygonum multiflorum Thunb. (known as Zhiheshouwu in Chinese medicine), exhibits anti-aging properties and is used to improve ovarian aging. However, its therapeutic mechanism against premature ovarian insufficiency (POI) remains unclear. This study investigates whether PMRP alleviates POI by inhibiting PANoptosis-a cell death pathway characterized by the concurrent occurrence and interplay of pyroptosis, apoptosis, and necroptosis. POI was induced in rats using tripterygium glycosides. We evaluated the estrous cycle, serum hormone levels (follicle-stimulating hormone [FSH], estrogen [E(2)], anti-Müllerian hormone [AMH]), follicular development, and the ultrastructure of granulosa cells. PANoptosome assembly (apoptosis-associated speck-like protein containing a CARD [ASC]/caspase-8/receptor-interacting protein kinase 3 [RIPK3] co-localization) and key effectors of PANoptosis (caspase 3, cleaved caspase 3, gasdermin D [GSDMD], cleaved GSDMD, GSDME, RIPK1, mixed-lineage kinase domain-like protein [MLKL], and p-MLKL) were analyzed. PMRP restored the estrous cycle, lowered FSH levels, and increased E(2) and AMH levels in POI rats. It reduced follicular atresia, preserved primordial follicles, and suppressed PANoptosis-like death in granulosa cells. Mechanistically, PMRP disrupted PANoptosome assembly and downregulated key effectors of PANoptosis. PMRP alleviates POI by inhibiting PANoptosis in granulosa cells, overcoming the previous limitations of targeting single death pathways and providing novel insights into the pathogenesis and treatment strategies for POI.