The burgeoning field of Positive Psychology in Second Language Acquisition (SLA) has underscored the importance of emotions in foreign language learning, predominantly focusing on anxiety, enjoyment, and boredom. Nevertheless, a broader range of emotions remains largely unexplored due to the absence of comprehensive assessment tools. This study contributes to filling this void by adapting and validating the Achievement Emotions Questionnaire-Foreign Language Learning (AEQ-FLL) to encompass eight prevalent emotions in the Chinese English as a Foreign Language (EFL) context. A total of 1008 high school students from 26 classes across two provinces participated in this study. The research employed rigorous methodological approaches including model comparisons, reliability assessments, and tests for convergent, discriminant, and external validity. The findings confirmed the robustness of the eight-emotion model within the AEQ-FLL. Furthermore, the study established that these emotions have significant correlations with control and value appraisals. Measurement invariance tests with increasing constraints further verified the stability of the AEQ-FLL’s factorial structure by showing scalar invariance across different age, gender, and school context groups. This study provided a reliable and valid instrument for measuring eight prevalent emotions in the EFL context, contributing to the evolving research landscape in foreign language learning emotions by pushing forward a more nuanced understanding of the emotional experiences of language learners.