The COVID -19 pandemic, as a global health emergency, has attracted a great deal of attention from the international community. In this context, China attaches great importance to economic development and news coverage because the economy concerns people's interests, while media coverage of the economy plays a crucial role in influencing citizens' attitudes and even social stability. While researchers from different disciplines are studying the epidemic, such as education, mental health, and vaccines, existing research into the media discourse of COVID-19 is limited, especially regarding its semantic and sentimental features, and it remains unclear whether the coverage of media news in different countries would draw on varying lenses. To this end, this study constructed a corpus of Chinese and American news reports from January 2020 to August 2021 and analyzed the meaning, lexicality, affective polarity, and theme extraction. Our results suggested that the mainstream media in China and the United States show opposite attitudes toward the same economic situation in China. Further, we interpreted this discrepancy in light of the “explanation” component of Fairclough's three-dimensional model. Such inconsistencies could relate to the differences in cultural backgrounds, modes of operation, and news philosophies between the two countries. Thus, by using a corpus-based approach combined with critical discourse analysis (CDA), our study not only broadens the scope of news discourse analysis, but also advances our understandings of the semantic and sentimental features of news coverage during COVID-19 and the possible reasons behind the differences between countries from a more macro perspective.