Autism Spectrum Disorder(ASD) is highly prevalent worldwide, and so far incurable, as one of its main symptoms is rigidity in behavior and mind. Cognitive flexibility is considered to be highly relevant to ASD. ASD afflicts individuals and their families severely, which can cause a broad range of social problems. For its incurable nature, alleviating its symptoms or discovering its cures is highly significant. The pathogenic factors of ASD are complex, and the inner differences among individuals with ASD vary a lot. ASD require individualized long-term intervention, including education and rehabilitation training based on wholesome assessments of an individuals psychological development, behavior, demand, and adaptive social capability. An extensive range of interventions is researched and implemented practically. However, the inherent flaws of these interventions are so far unsolved. In this article, mindfulness is discussed as a new intervention to gain a deeper insight into mindfulnesss effects on the cognitive flexibility of ASD children. Previous articles are reviewed, and though a relationship between mindfulness and cognitive flexibility in ASD is complex and indirect, the conclusion that mindfulness train is beneficial to the cognitive flexibility of ASD children is drawn eventually. Relevant research directions are recommended according to the conclusion.