Blended classroom assessment (CA) has become commonplace in the post-pandemic era, offering advantages but also presenting challenges for English as a Foreign Language (EFL) teachers. These challenges can impact teachers' emotional experiences, distinct from face-to-face or purely online environments. However, scant research exists on how EFL teachers employ emotion regulation (ER) strategies in blended CA within EFL contexts. This qualitative study examines how eight EFL teachers at a university in southwestern China employed ER strategies in blended CA. Drawing on Gross's ER theory, the study identifies ten intrinsic and extrinsic ER strategies, either antecedent-focused or response-focused, utilized by EFL teachers. These strategies helped teachers maintain resilience amidst challenges posed by blended CA, including low completion rates of online learning tasks prior to face-to-face instruction, interaction in blended CA, blended assessment design, managing the workload of blending online and face-to-face assessment, and addressing issues of plagiarism and cheating. The study enriches our understanding of EFL teachers' emotions in blended CA and underscores the significance of ER competence in assessment literacy. Implications for equipping teachers with strategies to enhance their emotional well-being and resilience in blended CA are also discussed.