The essence of six channels is a methodological model used to describe changes in complex systems.According to the evolution law of the hierarchy of complex systems

based on the interaction of complex system structures and functions

based on the connotation of six channels in Chinese medicine

the authors construct six channels substantial-function model. The model is based on the five elements substantial-function image model and includes a system of 3 levels. Taiyang-shaoyin system is the environmental level system. Yangming-taiyin system is the systematic level system. Shaoyang-jueyin system is the subsystem level system. This model may be used to explain many difficult problems in current study of six channels essence

such as five elements matching difference of six climatic factors and six channels

manifestation and root cause source-transformation of "theory from manifestation and root cause"

six channels open-close-pivot and overall pathogenesis characteristics of six channels diseases

which shows that six channels substantial-function model may reveal the scientific connotation of six channels and it is a successful application of thinking model in Chinese medicine field.