This study explores the professional identity construction of two transnational Chinese language teachers against a backdrop where multilingual and dynamic turns in language teaching and learning are taking place globally. Combining the complex dynamic system theory perspective with the multifaceted nature of language learning and teaching framework, and by adopting multiple sources of narrative data, it was found that both participants faced a downgrade in their professional identity due to the overpowering influence of English globally and locally, and the unequal transformation of cultural capital from the Chinese educational system to the English educational system also caused such a downgrade; the vulnerable identity of an ESL learner remained the most prominent aspect of their multifaceted teacher identity. As their English improved, they also made improvement in their career development, and it was the high-quality translanguaging practices enabled by the emergence of multilingual identities that empowered them to improve in their professions. The article ends with a call for actions to legitimize transnational language teachers' professional identity from a translanguaging perspective and to build a balanced sustainable language ecology.