Background: The impairment of immunity induced by high-carbohydrate diet is closely associated with the development of glucose metabolic disorders. In the study of diabetes, benfotiamine can prevent β-cell dysfunction by inhibiting inflammation, thereby improving insulin resistance. However, information regarding the effects of this substance on aquatic animals is extremely scarce.Methods: A 12-week nutritional research was conducted to evaluate the influences of benfotiamine on the growth performance, oxidative stress, inflammation and apoptosis in Megalobrama amblycephala (45.25 ± 0.34 g) fed high-carbohydrate (HC) diets. Six experimental diets were formulated, containing a control diet (30% carbohydrate, C), a HC diet (43% carbohydrate), and the HC diet supplemented with four graded benfotiamine levels (0.7125 (HCB1), 1.425 (HCB2), 2.85 (HCB3), and 5.7 (HCB4) mg/kg).Results: HC diet intake remarkably decreased daily growth coefficient (DGC), growth rate per metabolic body weight (GRMBW), feed intake (FI), liver antioxidant enzymes activities, sirtuin-1 (SIRT1) protein expression as well as liver mRNA levels of SIRT1, nuclear factor erythroid 2-related factor 2 (Nrf2), catalase (CAT), manganese superoxide dismutase (Mn-SOD), interleukin10 (IL10) than those of the control group, but the opposite was true for plasma activities of alanine transaminase (AST) and aspartate aminotransferase (ALT), and contents of interleukin 1β (IL1β) and interleukin 6 (IL6), liver contents of malondialdehyde (MDA), and mRNA levels of kelch-like ECH associating protein 1 (Keap1), nuclear factor kappa B (NF-κB), tumour necrosis factor α (TNF α), IL1β, IL6, Bax, Caspase 3, Caspase 9 and P53. As with benfotiamine supplementation, HCB2 diet remarkably increased DGC, GRMBW, liver antioxidant enzymes activities, SIRT1 protein expression as well as liver mRNA levels of SIRT1, Nrf2, CAT, Mn-SOD, IL10 and Bcl2, while the opposite was true for plasma activities of AST and ALT, and contents of IL1β and IL6, liver MDA contents as well as mRNA levels of Keap1, NF-κB, TNF α, IL1β, IL6, Bax, Caspase 3, Caspase 9 and P53.Conclusion: Benfotiamine at 1.425 mg/kg can improve the growth performance and alleviate the oxidative stress, inflammation and apoptosis of M. amblycephala fed HC diets through the activation of the SIRT1 pathway.