Insomnia symptom is one of the most common types of sleep disturbances.Apart from being a risk factor for psychiatric disorders, insomnia symptom has been found to affect the course of psychiatric disorders and increase the relapse rate of psychiatric disorders.Therefore, insomnia treatment is beneficial to mitigate the psychiatric symptoms among chronic insomnia patients, which may help prevent mental health disorders.On the other hand, insomnia treatment for psychiatric patients is conductive to reduce the harm consequence in social function, which can help improving the prognosis of psychiatric disorders.Cognitive behavior therapy for insomnia (CBT-I) is a first-line treatment for chronic insomnia.This paper reviews the research progress on the efficiency of CBT-I on the psychiatric symptoms of chronic insomnia patients, as well as its application in comorbid psychiatric conditions.Findings from previous research suggested that CBT-I is effective to improve the psychiatric symptoms of insomnia patients through insomnia improvement, and it can also promote the remission of depression and anxiety symptoms, reduce the risk of substance disorder and suicide behaviors, and reduce the impairment of life quality and costs of treatment through insomnia improvement among psychiatric patients comorbid with insomnia, which indicated that CBT-I is a safe and effective treatment for insomnia symptoms in psychiatric patients.Moreover, this paper listed the contraindications and the decision-to-treat algorithm of CBT-I among psychiatric patients, as well as the CBT-I availability and adherence that limited the clinical application.More understanding of CBT-I is beneficial to provide support for a broad clinical application in mental health services.