In this paper, an integrated analytical framework of “text structure-cognitive mechanism-social structure” is established and applied to corpus-assisted discourse analysis concerning the political discourse about ecological civilization with the aim of revealing the interactions and cognitive mechanisms of the interconnections between discourse structure and social structure. The analysis revealed that four thematic topics, namely ecology, civilization, construction, and governance, were constructed, and that three cognitive mechanisms, namely metaphorical frame, de/recategorization, and cultural schema, were mainly used. The correspondence and interaction between text structure and cognitive mechanisms point to the underlying dominant ideology, which is embodied as the ontology of socialist ecological civilization, dialectic materialism and methodology, and the traditional cultural stance. It is through the interactions of three dimensions, namely text structure, cognitive mechanisms, and social structure, that the discourse concerning ecological civilization effectively constructs a set of new thoughts about civilization, as well as the new norms of social practice. The production, reproduction, communication, and acceptance of such discourse serves the ideological function of reconstructing the view of civilization, regulating social actions, and envisioning the future. This social-cognitive study contributes to the construction of a discourse system for ecological civilization and enhances the discursive efficacy.