At the end of 2019, New Coronavirus first swept China and spread to the whole world, which affected almost all industries globally. Therefore, both the economy and the stock market in this world received a punch. This essay uses the Fama-French model to calculate the rate of return of a given asset in the meal industry. The periods chosen for this research are September 2019 to February 2020 and March 2020 to August 2020, which are before and during the Covid-19. Due to the impact of the Covid, to control the flow of people and prevent cross-infection, many public places were forced to close, so were restaurants. Therefore, the industry selected in this paper is the meal industry. In conclusion, because of the volatility of the US stock market, the shares of the beverage industry have also been seriously affected. Due to the epidemic's impact, large enterprises tend to overestimate themselves, but investors have fewer expectations of them. Therefore, although the risk of small enterprises in the catering industry is greater, the income of small enterprises is greater than that of large enterprises, and the small-scale effect is enhanced. Therefore, investors are more inclined to invest in small enterprises. In addition, Fama-French five-factor model also shows that investors are more inclined to choose companies with aggressive investment styles.