The study aimed to investigate how two English as a Foreign Language (EFL) teachers integrated their teacher and researcher identities to achieve sustainable professional growth in the context of a changing academic landscape. Using purposive sampling, two EFL teachers from a non-elite public university in China were selected as participants for this qualitative study. Data were collected and triangulated from multiple sources, including semi-structured interviews, narrative frames, document analysis, and the academic profiles of the participants. A qualitative, inductive thematic approach was employed in the data analysis. Adopting "identity" as an analytical lens, this study examined how the two participants underwent different identity trajectories to develop into teacher-researchers under the influence of their personal values and beliefs, as well as contextual factors such as institutional research policy. Throughout their identity construction process, the two participants encountered identity deficits and tensions between multiple professional roles, leading to their struggles with identity and complex identity (re)construction. While the participants underwent interactions between various forms of identity throughout their careers, they enacted agency to take actions and draw on available resources to address their identity deficits and conflicts, ultimately resolving them by pursuing a sustainable career path as teacher-researchers in their situated socio-institutional environment. Despite their different identity trajectories, the construction of the participants' teacher-researcher identity facilitated their continuing professional development. This study contributes to our understanding of the complexities of EFL teachers' identity (re)construction when seeking to establish sustainable career paths in a changing academic context. This study also has implications for both EFL academics and university management on how to assist EFL teachers in integrating teacher and researcher identities to achieve sustainable professional development in higher education.