Given the growing incidence of dementia-related disorders in the aging population, identifying effective treatments for age-related cognitive decline (ARCD) is crucial. Shenwu Capsule (SWC), shown to have therapeutic efficacy in phase III clinical trials for senile dementia, has unclear mechanisms and active ingredients. Aged mice were administered SWC orally for three months, and behavioral tests, including the Morris water maze, Y maze, and novel object recognition, assessed learning and memory. Neuronal damage was evaluated using histopathology, and the levels of Aβ and phosphorylated tau proteins were measured. UPLC-Q-TOF-MS identified 11 components of SWC capable of crossing the blood-brain barrier (BBB), and network pharmacology was employed to explore their potential mechanisms. Through various detection methods, including transmission electron microscopy, Western blotting, qRT-PCR, ELISA, and immunofluorescence, six key targets (AKT1, TNF, TP53, SRC, EGFR, BCL2) were elucidated. GO and KEGG pathway analyses revealed that the PI3K/Akt signaling pathway plays a crucial role in the pharmacological effects of SWC. SWC was found to suppress neuronal apoptosis by activating the PI3K/Akt/Bcl-2 signaling pathway, as demonstrated by changes in mRNA and protein levels. Histological analysis further showed that SWC treatment restored mitochondrial morphology in the hippocampus of aged mice. Molecular docking simulations confirmed strong binding affinities between the active components and key targets. Psoralidin, a component with strong molecular docking potential, was shown in vitro to activate the PI3K/Akt/Bcl-2 pathway, reduce ROS, decrease apoptosis, improve mitochondrial morphology, and stabilize mitochondrial membrane potential. These protective effects were blocked by the PI3K inhibitor LY294002. Overall, SWC ameliorates ARCD through modulation of the PI3K/Akt/Bcl-2 signaling pathway, with psoralidin identified as a potential active ingredient.