With the maturity of theoretical research, the application of linear regression analysis in daily life is more and more frequent. This paper first introduces the origin of the word "regression", and then leads to the theory of unitary linear regression on the basis of correlation analysis. Then I explained another analysis method in detail, and briefly introduced how to use Excel to do the analysis. All the above are based on the introduction and discussion of statistical examples of daily life. Finally, the practical application of linear regression in various fields is introduced.