Insomnia and anxiety have a relatively independent but interactive relationship.Insomnia can cause the aggravation of anxiety,and anxiety can also cause recurrent attacks of insomnia.In the form of comorbidity,the two frequently coexist.By systematically reviewing the literature,we found that the mechanism of insomnia combined with anxiety is complex,but the most important ones are 5-hydroxytryptamine system,hypothalamic pituitary adrenal axis,Orexin and its receptor pathway,dopamine,Neuroactive Ligand-Receptor Interaction Signaling Pathway,and other neuro-biological pathways.