The full name of PMI index is purchasing management index in English, and it is translated into purchasing managers index in Chinese. PMI is a comprehensive economic monitoring index system released every month. The PMI business reports of manufacturing and non-manufacturing industries are released on the first and third working days of each month, which is far ahead of the statistical reports of other government departments, and the selected indicators are ahead. Therefore, PMI has become a timely and reliable leading indicator for monitoring economic operation, and has been widely recognized by the government, business circles, economists and forecasting experts.

After the PMI is calculated, it can be compared with last month. If the PMI is greater than 50%, it means that the economy is rising, and vice versa. Generally speaking, the aggregate composite index of manufacturing industry is higher than 50%, which means that the whole manufacturing economy is growing, and lower than 50% means that the manufacturing economy is declining.

PMI index system is of great significance to the economic forecast and business analysis of government departments, financial institutions, investment companies and enterprises. PMI index is highly correlated with GDP, and its inflection point is often several months ahead of GDP, which is an important basis for government regulation, financial institutions and investment companies to make decisions. In addition, enterprises can use PMI to judge the supply level and overall trend of the industry in time and analyze the advantageous industries.