Mathematical model can be described as: for a specific object in the real world, for a specific purpose, according to its inherent system characteristics and laws, make certain necessary assumptions, and express a mathematical structure in a generalized or approximate way with mathematical language, which is a pure relational structure of a system depicted by mathematical symbols. The generalized mathematical model includes various concepts, formulas and theories in mathematics. The mathematical structure obtained on the basis of certain abstraction and simplification, that is, the mathematical model, can help people to understand the research object more deeply. In a narrow sense, mathematical model only refers to the mathematical relationship structure that reflects a specific problem or a specific thing system. In this sense, it can also be understood as a mathematical expression, which describes the relationship between variables in the system.