Abstract: Multisensory processing is a fundamental cognitive function that underlies perception, attention, memory, language, and learning. Understanding the neurocognitive mechanisms of this function is of great theoretical and practical significance for understanding the principles of the human mind and for guiding the development of multisensory artificial intelligence. However, the mechanisms of multisensory information processing are extremely complex, and systematic review is essential for accurately understanding the cutting-edge progress in this field and inspiring future research. In this review paper, we first introduced the functional characteristics and response principles of multisensory neurons in the brain. Then, we discussed the mechanisms of cross-modal modulation between primary cortical areas. After that, we focused on the functions and computational mechanisms of multisensory areas and hierarchical multisensory brain networks. Lately, we discussed how studying human multisensory processing can inform the development of multisensory artificial intelligence.