In recent years, the neural mechanism of general anesthesia has become a research hotspot in the field of neuroscience and anesthesiology. The structural and functional integrity of the thalamocortical circuit is essential for the maintenance of consciousness. This review summarized the neuroanatomical and neurophysiological characteristics of the thalamocortical circuit and research progress on its role in unconsciousness induced by general anesthetics, which will provide new thoughts for a comprehensive understanding of the mechanism of general anesthetics and the physiological mechanism of generation and maintenance of consciousness.