This study investigates the perception-practice gap among English teachers in China concerning the integration of social media into teaching, blending the Language Teacher Cognition (LTC) framework with the Technological Pedagogical Content Knowledge (TPACK) model. A mixed methods approach, including the adoption of online questionnaires, instructional documents and semi-structured interviews was utilised to investigate these research questions from different perspectives. We collected 119 valid questionnaires. From these, we selected seven volunteers—those who provided their contact information and represented a range of demographic profiles—for further study. Seven instructional documents were gathered from these volunteers. Subsequently, follow-up interviews were conducted with these selected participants to gain deeper insights into their experiences and perspectives. The study revealed a significant discrepancy between moderately high perceptions and relatively low practices. This dynamic and bi-directional gap is influenced by microscopic factors like schooling and affective issues, as well as macroscopic factors such as institutional and societal influences. These factors constitute a layered system. The findings illuminate the complexities underlying the perception-practice gap in English teaching with social media integration, offering theoretical, methodological, and practical implications.