The effects of a phosphatidylserine-walnut peptide complex (PSWP) on scopolamine-induced memory impairment in mice were investigated. Cognitive performance was evaluated using behavioral tests, while acetylcholine (ACh) levels and acetylcholinesterase (AChE) activity were determined using ELISA kits. Histopathological changes in hippocampal tissue were assessed using hematoxylin-eosin (H&E) staining, and gut microbiota composition was analyzed using 16S rRNA gene sequencing. The results showed that, compared with the model group, PSWP significantly improved learning and memory performance. In the low-dose (0.45 mg•g-1), medium-dose (0.90 mg•g-1), and high-dose (1.35 mg•g-1) groups, escape latency was reduced by 35.25%, 60.05%, and 64.82%, respectively; the number of platform crossings increased by 116.67%, 345.83%, and 304.17%, respectively; and the percentage of swimming distance in the target quadrant increased by 21.73%, 72.21%, and 30.91%, respectively. Meanwhile, ACh levels increased by 12.41%, 25.67%, and 19.86%, and AChE activity decreased by 20.43%, 46.24%, and 40.32%, respectively. PSWP administration also alleviated hippocampal pathological damage in memory-impaired mice. Furthermore, medium-dose PSWP significantly increased gut microbiota diversity. The relative abundances of norank_f_Muribaculaceae, unclassified_f_Lachnospiraceae, and Eubacterium_xylanophilum increased by 184.74%, 224.98%, and 822.32%, respectively, whereas those of Allobaculum and Ileibacterium decreased by 68.09% and 96.18%, respectively. Correlation analysis revealed that the memoryimproving effects of PSWP were closely associated with modulation of the cholinergic system and gut microbiota composition. Overall, PSWP effectively improved memory impairment in mice, providing a theoretical basis for its application as a functional ingredient targeting cognitive dysfunction.