Abstract: Ecological affordance theory, originally proposed by Gibson, emphasizes the dynamic interaction between the organism and the environment. It was later introduced into the field of second language acquisition (SLA) by van Lier, who reconstructed the ontological framework of language learning. This study systematically reviews its philosophical foundations and theoretical implications, and employs CiteSpace to analyze 526 publications from the Web of Science database, revealing international research trends: an initial focus on classroom discourse analysis, a mid-term shift toward information technology and multimodal studies, and recent deepening into generative artificial intelligence (GenAI)-assisted learning, emotion integration, and translanguaging. Findings indicate that although progress has been made in technological applications, sociocultural integration, and interdisciplinary approaches, limitations remain in conceptual generalization, empirical evidence, and localization. Notably, GenAI research largely centers on tool functionality, lacking a return to the essence of the organism–environment system. To this end, this paper hopes to deepen the theoretical and practical values of Ecological Affordance Theory as a framework for SLA.