In the modernization process of Chinese language, many Japanese loanwords have been added. They were brought back to China by students studying in Japan. Therefore, these Japanese loanwords, many of which become vocabulary of Chinese language, are also written in university textbooks. In addition to Hong Kong, Macao and some of Malaysia's overseas Chinese students, many overseas Chinese students study Chinese as a second language. How to make the overseas Chinese students adapt to textbooks in Chinese in a short time, is the key to language teaching for overseas Chinese students. This study used questionnaires to summarize the overseas Chinese students' understanding of Japanese loanwords. Through analysis, we can try to find out the difficulties of overseas Chinese students learning Chinese language as a second language. And it can not only improve the efficiency of Chinese language teaching to overseas Chinese students, but also the academic adaptability of overseas Chinese students.