Policy discourse is a process of social practice and cognition as well as important semiotic resources of social culture and political interaction. This investigation on the evolution of social labels to migrant workers finds that Chinese migrant workers’ policy discourse can not only construct social reality but also is restricted by social structures. Chinese political philosophy on migrant workers is transforming from serving economy to emphasizing migrant workers’ social life. This transformation witnesses and promotes the social change in national population movement from rural regions to urban cities, which has undergone a sequential process of strict restriction, free movement to gradual citizenization. This study reveals that deconstruction on microdiscourse with the theoretical foundation of critical discourse analysis is an effective way to analyze policy discourse, helpful to awaken more profound and rational policy negotiation, and to facilitate social justice.