The present disclosure provides a high-activity memory-improving derivative peptide and use thereof in preparation of memory-improving medicaments, health care products or foods, and belongs to the field of biotechnology. According to the present disclosure, proline 3 (Pro3) of a pine nut high-activity memory-improving peptide, WYPGK, is completely substituted with common amino acids to obtain 19 derivative peptides, and the derivative peptides are subjected to molecular docking with mitochondrial deacetylase sirtuin 3 and are screened by binding energy to obtain derivative peptides WYEGK, WYKGK, WYSGK, and WYFGK; solid-phase chemical synthesis is conducted by a peptide synthesizer; the derivative peptides are purified by reversed phase high performance liquid chromatography (RP-HPLC) and prepared by electrospray ionization mass spectrometry (ESI-MS). Morris water maze for scopolamine-induced memory impairment model mice demonstrates that the derivative peptides have high memory-improving activity.