The present research investigates the acculturation attributes and psychological mechanism of Chinese Second Language（CSL）learners living in China. Three empirical studies are carried out with questionnaires designed on the basis of the framework of culture mixing and acculturation theory. In Study 1，a case of emergent psychological crisis is described and the symptoms of culture shock are analyzed through in-depth interview. Study 2 is a preliminary investigation among a sample of 52 foreign students who were studying Chinese in Guangzhou. The results show that acculturation of CSL learners follows a U-shape curve，which is mainly caused by their feeling of homesick and anxious attachment relationship with the Chinese culture. Study 3 examines the impact of acculturation on CSL learners and how they reduce acculturation stress. A total of 110 foreign students in Beijing and Guangzhou participated in the internet-based survey. A mediation analysis was conducted，and the results showed that homesick triggered anxiety and tension about Chinese culture，followed by a sense of acculturation stress，which further affected their cultural exploration，cultural commitment and learning satisfaction in China. Nevertheless，this stress can be partially reduced by the experience of active Chinese culture exposure，especially making good friends with Chinese.