The COVID-19 pandemic has caused severe imbalances in the global economy and intensified stock market turmoil worldwide. Based on Fama-French five-factor model, this paper studies Chinas A-share market changes before and after the epidemic. The stocks treated by ST (special treatment) and * ST (delisting warning) are screened, excluding companies and banking stocks with shortlisting time. The equities are finally divided into groups using the two-by-three grouping approach. According to the median of the total market value of stocks, the entire sample is separated into two categories: modest market value (S) and large market value (B). The samples are classified into three categories based on the book-to-market ratio's 30% and 70% quantiles: high (H), medium (N), and low (L). Comparing the different times of the impact of the five factors on stock earnings is conducive to explaining the changes in the factors affecting the stock price of listed companies before and after the epidemic. It is possible to analyze which factors have declined and fluctuated after the epidemic, resulting in a decline in stock prices, a slowdown in the growth of listed companies, or even a recession. The analysis of the five-factor model can clarify which factors have led to the decline in stock prices after the beginning of the epidemic, which is conducive to the formulation of related policies and plans by listed companies and makes up for the decline in stock prices and the slowdown in company growth caused by the corresponding decline, which has apparent practical value.