Abstract: Insomnia disorder is one of the most common sleep disorders with an increasing incidence to cause substantial economic losses and social burden. The therapy for insomnia disorder mainly includes medication treatment and cognitive behavioral therapy. Medications are associated with various adverse effects and can be easily addictive. Cognitive behavioral therapy has been proposed as the first-line treatment for insomnia disorder. But due to the disadvantages of face-to-face cognitive behavioral therapy including a high cost and the lack of standardization, internet-based cognitive behavioral therapy has emerged as an alternative with an almost equivalent efficacy to face-to-face cognitive behavioral therapy and better effects than medication. This review summarizes the basic principles of cognitive behavioral therapy for insomnia and discusses the development, forms, effects as well as the advantages and disadvantages of internet-based cognitive behavioral therapy.