Chinese migrant workers have contributed greatly to the industrialization and urbanization of China and have thus long been a popular topic in news reports. Most previous studies on the news about this group have been qualitative or quantitative analyses based on small-scale datasets, with few based on large-scale corpus data. This study combined topic modeling and critical discourse analysis (CDA) to analyze 186,180 reports of migrant workers published by 906 Chinese newspapers between 2001 and 2021. We identified seventeen topics in the news that fell into five categories: “work and labor,” “support and care,” “rights and interests,” “homecoming,” and “social emergencies.” Overall, news reports on the group have become increasingly diverse, with various diachronic changes in the proportions of topic categories and specific topics. In addition, we found three major types of representation of migrant workers: as a disadvantaged group, as outsiders, and as a group vulnerable to risks. These negative representations might be closely related to government policies, ideology, media stance, and social reality (the broader societal context in which these individuals are situated).