•Hydrogen water (HW) treatment significantly delayed pericarp browning of litchi.•HW treatment maintained fruit quality of litchi during postharvest storage.•GSH and secondary metabolites played vital role in HW-delaying pericarp browning of litchi.•H2O2 might play a positive role in HW-delaying pericarp browning of litchi. Litchi fruit were exposed to 0.7 PPM hydrogen water (HW) before storage at 25 ± 1 ℃. HW treatment delayed the pericarp browning and maintained the total soluble solids (TSS) of litchi fruit. Then, a total of 25 antioxidant system-related characters were determined to evaluate the effects of HW on antioxidant system during pericarp browning. Compared with control pericarp, the pericarp of HW-treated litchi fruit exhibited higher levels of superoxide radical (O2−·) scavenging activity, glutathione (GSH), monodehydroascorbate reductase (MDHAR), polyphenol oxidase (PPO) and total flavonoids during whole storage, higher levels of hydrogen peroxide (H2O2), catalase (CAT), glutathione disulfide (GSSG), ascorbate oxidase (AAO) and total phenols only on day 1, and higher levels of ascorbate peroxidase (APX), total anthocyanin, glutathione reductase (GR) and glutathione peroxidases (GPX) at later stage of storage. Those HW-induced antioxidant system-related characters might directly or indirectly enhanced the antioxidant capacity and delayed the pericarp browning of litchi.