In terms of the theory of visceral manifestation， “the interior-exterior relationship between the heart and small intestine” is one of its theoretical cores. This article mainly searched the ancient Chinese medicine books in “Expo Medical Books - Database of Ancient Chinese Medicine Books”（www.imedbooks.com）， systematically organized and analyzed relevant ancient books， and sorted out the historical origin and development of the theory of “the interior-exterior relationship between the heart and small intestine”. It is believed that this theory， originated in the Qin and Han dynasties， was formed in the Jin， Sui， and Tang dynasties， developed in the Song， Jin， Yuan， matured in the Ming and Qing dynasties， and changed in the late Qing and early Republic of China. This paper also explored the ascribing of channels and collaterals， the physiology and pathology relationship， pathogenesis and clinical differentiation and treatment of “the interior-exterior relationship between the heart and small intestine” theory， which helps to establish the systematic logic of this theory， dig deeper into the theory's essence，inspire traditional Chinese medicine （TCM） thinking， and guide TCM clinical practice.