Among many macroeconomic data, a particularly important indicator is the change of consumer price index (CPI index), which reflects the change of the price level of consumer goods and services purchased and used by urban and rural residents to reflect the degree of inflation. The composition of CPI data in China can be basically divided into two categories: non-food and food. Among them, food elements account for about 33.2% of CPI, and non-food elements account for about 66.8% of CPI.