Based on data from 263 Chinese prefecture-level cities from 2013 to 2022, this study examines the impact of the digital economy on the quantitative toughness of employment and the moderating role of industrial agglomeration. The study finds that: first, there is a significant U-shaped relationship between the digital economy and the quantitative toughness of employment, i.e., it may inhibit employment in its early stages, but the facilitating effect gradually emerges as it develops. Second, manufacturing agglomeration, productive services agglomeration and cooperative agglomeration significantly moderated this relationship, in which manufacturing and cooperative agglomeration delayed the positive impact of the digital economy, while productive services agglomeration flattened the U-shaped relationship and gradually transformed it into a positive linear relationship. Finally, the test of regional heterogeneity and city size shows that the U-shaped relationship between the digital economy and employment resilience is more significant in the eastern region, but not in the central and western regions; the impact of each city size is diversified, with a U-shape for Type I large cities, a positive linear relationship for Type II large cities, and a negative linear relationship for small cities. The study deepens the understanding of the impact of the digital economy on the labor market, and provides empirical support for policymakers to balance between digital economy development and employment optimization.