The Internet serves as a shared discourse arena where hundreds of millions of people interact and integrate, exerting a profound influence on people’s ideological cognition and values. The discourse representation of the mass line and populism in the digital age determines that there are superficially similar but essentially different differences between the two discourse systems in terms of their discourse paradigms, characteristics, forms, objectives and construction. Specifically, they differ fundamentally in their theoretical foundations and basic connotations, main characteristics and functions, discourse modes and narrative frameworks, value orientations and practical effects, as well as practical strategies and pathways. A scientific analysis of the similarities and differences in discourse between the mass line and populism helps clarify their essential differences, which is of great practical significance to further deepen the theoretical and practical research on the mass line in the digital age and prudently respond to the impact of populism.