Autism spectrum disorder（ASD）is a neurodevelopmental disorder that originates in early childhood. The precise pathogenesis of ASD remains unclear，and current interventions show limited effectiveness in improving patient outcomes. Various treatment strategies are being explored.The ketogenic diet（KD），as a high-fat，low-carbohydrate，moderate-protein diet，gains attention as a potential therapeutic option for ASD. This article reviews the current application of the KD in the treatment of ASD，with a detailed exploration of its efficacy in alleviating ASD symptoms，clinical uncertainties，and potential mechanisms of action. These mechanisms include its effects on gut microbiota，neural excitation-inhibition balance，inflammation，oxidative stress，and so on. The review aims to provide reference for further scientific research and practical clinical applications.