Mental disorders are a type of behavioral, emotional, cognitive, or thinking disorder that cause pain and social dysfunction, and are one of the top ten global disease burdens. Cannabidiol (CBD) is one of the main components of cannabis, with high safety and tolerability, and is a hot topic in drug research. CBD has a wide range of therapeutic effects, and research has found that CBD has neuropsychiatric effects such as anti-addiction, anti-depression, anti-anxiety, and anti-stress, making it one of the candidate drugs for mental disorders. This article summarizes the mechanism and research progress of CBD for major mental disorders, in order to provide useful references for CBD-related compounds in the treatment of mental disorders.