Through an intertextual analysis of policy documents, this study examines how language ability has been constructed as a key technology in Korean migration policy. Drawing on Foucault’s concept of governmentality and critical discourse analysis, this paper treats policy texts not as neutral administrative instruments but as discursive practices that legitimize language assessment as a condition of eligibility, integration, and citizenship. Focusing on documents related to Korean language testing, naturalization requirements, and social integration programs, this analysis highlights how recurring discourses on standardization, social order, and risk management have bee mobilized to acclimatize language evaluation. Rather than reporting the empirical outcomes of language testing, this study offers a critical reading of policy discourse, showing how language ability is framed as an objective and technical criterion, while obscuring its political and normative implications. This study contributes to the sociolinguistic and critical language policy research by illuminating how language assessment operates as a powerful mechanism for selection and governance in contemporary migration regimes.