<p>Based on the holistic concept of body-spirit unity and philosophical reasoning of Traditional Chinese Medicine (TCM), this study proposes the “Mind-Cognition-Emotion” system model (MCESM). It organizes mental activities into three levels: Mind Domain (<i>Jing</i>,<i> Shen</i>,<i> Hun</i>,<i> Po</i>), Cognitive Domain (<i>Yi</i>,<i> Zhi</i><i> Si</i>,<i> Lü</i>,<i> Zhi</i>), and Emotional and Affective Domain (<i>Qing</i>,<i> Yu</i>,<i> Hao</i>,<i> Yuan</i>). We investigate the formation, development, and transformation of individual mental, cognitive, and emotional states. The specific components of MCESM are delineated, and the functional mechanisms, physiological attributes, and pathological alterations of mental activity are analyzed. By integrating fundamental TCM theories, it establishes the interconnection between the physical body and mental processes, linking psychological elements to physiological mechanisms, particularly in relation to organ function, qi dynamics, and qi-blood interactions. Furthermore, using depression as an example, the MCESM model is applied to illustrate its differential impact across three stages, guiding the selection of TCM-based mind-body treatments. Corresponding therapeutic approaches are presented.</p>