Industrial concentration refers to the proportion of the output or output value of the top few enterprises in a certain industry, which reflects the degree of industrial market monopoly. Industry concentration is mainly affected by the size and number of companies in the industry. Industrial concentration can be measured using a concentration index (such as industry concentration CRn, Hefindar index HHI), Lorentz curve, and Gini coefficient. Among them, CRn = the output of the top n enterprises in the output / total output of the industry * 100. The greater the value of CRn, the higher the level of industrial concentration and the closer the industrial market is to the monopoly market. Due to the incomplete collection of data on industry concentration, only the data from 2015 to 2019, the calculation results are as follows