Ketogenic diet(KD)is a formulation diet with a high proportion of fat, low proportion of carbohydrates, appropriate protein and other nutrients, which has been used for centuries in the treatment of refractory epilepsy.In recent years, KD has been shown to be effective in the treatment of other diseases, such as amyotrophic lateral sclerosis, traumatic brain injury, diabetes, obesity, etc.Although KD has a positive effect on the treatment of a variety of diseases, the short-term and long-term adverse reactions caused by the imbalance of its nutritional structure should not be ignored.This article reviews the adverse reactions of KD in the treatment of children with refractory epilepsy and the corresponding prevention and treatment measures, to guide safe and efficient implementation of KD therapy in the clinic.