Fast food refers to popular catering that commercial enterprises quickly supply. The fast-food industry, which can be processed quickly and eaten anytime and anywhere, has become increasingly important in the wake of COVID-19. The purpose of this article is to study the different factors that affect the sales revenue of the fast-food industry. This study took two approaches to examine the elements that influence sales income. It is from the perspective of affecting commodity prices, and on the other hand, it is to analyze the factors affecting sales. The results are generally in the whole fast-food industry, and it demonstrates two things. Firstly, market supply and demand affect price fluctuations, which affect the sales volume of the fast-food industry. Secondly, there are positive relationships between delivery systems, e-commerce, advertisement, and sales volume. Indeed, their relationships are particularly strong during the pandemic. The contribution of this work is presented as follows: it can help the catering industry to stay strong under the strike of the global pandemic.