Obsessive-compulsive disorder (OCD), as a kind of disease with early onset, complex etiology, psychological and mental diseases in which patients feel the most painful, often causes great life troubles and impaired social functions. For this reason, the treatment of obsessive-compulsive disorder has become a research hotspot. Cognitive behavioral therapy (CBT) is a kind of treatment method which is effective, mature, developing and innovative among many ways to treat obsessive-compulsive disorder. The purpose of this article is to introduce the theory of obsessive-compulsive disorder and its cognitive behavior. It will facilitate the development of the clinical research of obsessive-compulsive disorder.