This study examines a student's translingual practices and language ideologies in her academic writing process in a transnational higher education (TNHE) context to explore how translingual practices can help increase students' critical language awareness (CLA), which has been found to prevent under monolingual ideologies. A case study was adopted to collect the student's screen recordings, stimulated recall interviews, and written products pertaining to one of her academic writing projects. The findings reveal a translingual feature of her language practices but a monolingual orientation to her language ideologies. This mismatch indicates the necessity of raising students' CLA in TNHE contexts, especially those with an English medium instruction (EMI) policy. Pedagogical implications, such as involving translingual practices in self-reflective writing, discussing social justice issues based on these translingual writing practices, and promoting rhetorical agency by challenging native speakerism/monolingualism, are provided to help increase CLA through translingual practices in EAP writing education. This study enriches the theoretical purport of scholarship on translingual practice (Canagarajah, 2018) and argues for the pedagogical values of increasing CLA through translingual practices in EMI-TNHE contexts.