The present study investigated the effects of combined treatment with hyperbranched poly-L-lysine (HBPL) and chitosan (CS) on the storage quality of shiitake mushrooms (Lentinus edodes) at 4degree celsius for 15 days. The results demonstrated that HBPL-CS treatment effectively preserved the sensory quality of shiitake mushrooms, which remained satisfactory even after 15d of storage. After 15 days of storage, the rot degree, browning degree, and mass loss of shiitake mushrooms in HBPL-CS treatment group were 0.57, 3.85, and 9.31%, respectively, which were significantly lower than other treatment groups (p < 0.05). Meanwhile, the contents of reducing sugar, vitamin C, soluble protein, and total phenolic in HBPL-CS treatment group were 2.76 mg/g, 3.71 mg/100 g, 3.89 mg/g, and 0.42 mg/g, significantly higher than other treatment groups (p < 0.05). Furthermore, HBPL-CS treatment effectively suppressed malondialdehyde (MDA) accumulation and decreased relative electrolyte leakage in shiitake mushrooms (p < 0.05). Additionally, HBPL-CS treatment enhanced catalase (CAT), superoxide dismutase (SOD), and phenylalanine ammonialyase (PAL) activities while inhibiting peroxidase (POD) and polyphenol oxidase (PPO) activities in shiitake mushrooms. In conclusion, HBPL-CS treatment exhibited remarkable potential for preserving membrane integrity, delaying browning occurrence, and extending the shelf life of shiitake mushrooms.