Abstract： Image-thinking is a cognitive approach of traditional Chinese medicine with "observing objects to acquire images" as its core. Through methods such as "categorizing by images" and "inferring internal conditions from external manifestations，" it connects nature，human body，and disease phenomena，and constructs the diagnosis and treatment system of "image-principle-syndrome-treatment. " Based on the three dimensions of "correspondence between human and nature，" "visceral functions"， and "external manifestations of emotions， " image-thinking analyzes the etiology and pathogenesis of insomnia，and systematically expounds its practical path in clinical diagnosis and treatment by combining Chinese medicine prescriptions with non-drug therapies such as acupuncture， auricular points， and conduction or guiding and pulling.