This study explores the direct and indirect effects of linguistic identification and learning motivation, specifically the L2 Motivational Self System (L2MSS), on Chinese oral proficiency, focusing on complexity, accuracy, and fluency (CAF). The participants were 203 Chinese as a Second Language (CSL) learners recruited from regions and countries participating in the Belt and Road Initiative. Structural equation models (SEMs) were employed to analyse the data. The results demonstrate that linguistic identification contributed to Chinese oral complexity directly, but showed weak or no direct influence on accuracy or fluency. Although learning motivation exerted a weak influence on Chinese oral accuracy, it mediated the path from linguistic identification to oral accuracy. Finally, it was found that linguistic identification significantly influenced learning motivation. This study contributes to the research on second language (L2) learning from a sociocultural perspective, and provides implications for CSL teaching and learning.