The increasing adoption of Collaborative Learning Approach (CLA) in English as Foreign Language (EFL) education necessitates reliable and valid instruments for assessing its effectiveness. This study details the development and validation of a comprehensive instrument set designed to evaluate CLA's impact on English listening and speaking skills among Chinese EFL students at Qinghai University for Nationalities. In this unique multi-ethnic educational institution. The researcher developed and validated key instruments: a student questionnaire for evaluating learning experiences, measuring language proficiency. Results indicate high reliability (Cronbach's alpha > 0.85) and strong construct validity through confirmatory factor analysis (CFA loadings > 0.70) for the instrument. This research contributes significantly to the methodology of assessing collaborative learning in EFL contexts, particularly in multi-ethnic educational settings where traditional teaching methods intersect with innovative collaborative approaches.