Objective To investigate the effect of tea polyphenol (TP) on oxidative damage in a photoaging mouse model by regulating adenosine monophosphate-activated protein kinase (AMPK)/silent mating type information regulation 2 homolog 1 (SIRT1)/peroxisome proliferator-activated receptor γ coactivator-l (PGC-1) signaling pathway. Methods A photoaging mouse model was constructed by subcutaneous injection of D-galactose combined with ultraviolet (UVA+UVB) irradiation, successfully modeled mice were randomly grouped into model group, TP low, medium, and high dose groups (50, 100, 150 mg/kg), and positive control group (vitamin E 30 mg/kg) using a random number table method, with 12 mice in each group, another 12 mice were selected to be fed under normal light as the control group, each group was given corresponding medication, gavage once a day for 30 consecutive days. After the administration, mice in each group was evaluated for skin wrinkle grading; HE and Masson staining were applied to observe the pathological damage, epidermal layer thickness, and fibrosis degree of mouse skin tissue; immunohistochemical method was applied to measure the expression of type Ⅰ collagen (COL-Ⅰ) and type Ⅲ collagen (COL-Ⅲ); enzyme biochemical method was applied to measure the levels of superoxide dismutase (SOD), catalase (CAT), hydroxyproline (Hyp), and malondialdehyde (MDA) in skin tissue; enzyme linked immunosorbent assay (ELISA) was applied to detect the levels of interleukin-6, interleukin-1β (IL-6, IL-1β), and tumor necrosis factor-α (TNF-α) in mouse skin tissue; Western blot was applied to detect the expression of matrix metalloproteinase-1, -9 (MMP-1, MMP-9), and AMPK/SIRT1/PGC-1 signaling pathway proteins. Results Compared with the control group, the skin score, epidermal layer thickness, MDA, IL-6, IL-1β, TNF-α levels, and MMP-1 and MMP-9 expression of mice in the model group were obviously increased, the collagen content, SOD, CAT, Hyp levels, COL-Ⅰ, COL-Ⅲ, p-AMPK/AMPK, SIRT1, and PGC-1 expression were obviously reduced (P＜0.05); compared with the model group, the skin score, epidermal layer thickness, MDA, IL-6, IL-1β, TNF-α levels, and MMP-1 and MMP-9 expression of mice in the low, medium, and high dose TP groups and positive control group were obviously reduced, the collagen content, SOD, CAT, Hyp levels, COL-Ⅰ, COL-Ⅲ, p-AMPK/AMPK, SIRT1, and PGC-1 expression were obviously increased (P＜0.05). Conclusion TP may inhibit oxidative stress by activating the AMPK/SIRT1/PGC-1 signaling pathway, and have an improvement effect on skin photoaging induced by D-galactose combined with UVA+UVB radiation