Abstract： The meridian sinew theory， as a core component of the meridian and collateral theory in traditional Chinese medicine （TCM）， holds significant academic value and broad prospects for clinical application. However， current academic understanding of its anatomical essence predominantly focuses on connective tissue structures such as fascia and ligaments in modern anatomy. Debate persists over whether muscle tissue belongs to the meridian sinew system， and there remains a lack of systematic understanding regarding the relationship between the meridian sinews and the zang-fu organs. This article， grounded in classical TCM theory and integrated with modern anatomy， systematically explores the anatomical essence of the meridian sinew system. It posits that the superficial meridian sinew essence encompass fascia，ligaments，and skeletal muscles，while the internal meridian sinew essence uses the triple energizer and membrane source as their carriers. Regarding treatment， the article proposes a holistic strategy of "relieving meridian sinew masses externally and regulating the zang-fu organs internally，" providing a theoretical basis for the diagnosis and treatment of meridian sinew disorders.