Concept is a regular attribute of perceived things, usually marked by proper nouns or symbols; Proposition is a statement of the phenomenon, structure and law of things. In the concept map, a proposition is the meaning relationship between two concepts through a conjunction. Cross-connection represents the relationship between concepts in different knowledge fields; Hierarchical structure is a way to show concepts. Generally speaking, the general and most generalized concepts are placed at the top of the concept map, and the subordinate concepts are arranged below. The knowledge of leading cities can also be considered to provide relevant literature and background knowledge through hyperlinks. Therefore, the concept map is a spatial network structure diagram that represents the relationship between concepts.