English as a global language has received significant attention around the world. In China, people regard English as a foreign language, and many students may have no chance to use it after graduating. However, the government is still making a lot of efforts in reforming English teaching, in order to improve the quality of English teachers and raise students' awareness of language learning. During the reform, language teachers, especially college language teachers, are encouraged to speak pure English in class, to give students more chances to practice their communicative skills in the target language. However, the reality is quite different and a phenomenon called “code-switching” is often observed in EFL classes. Code and code switchingAccording to Bernstein (1971), code refers to a set of signals that carry meaning, such as language. Wardhaugh (2000) also states that code is “any type of system used by two or more people to communicate” (p. 86). In social community, people use language to talk with each other and share different points of view, so language is a typical type of code. Cook (2000) views code-switching as a process of switching from one language to another in the middle of a conversation when all speakers know the languages. Lightbown (2001) defines code-switching as “the systematic alternating use of two languages ​​or language varieties within a single conversation or utterance” (p. 598). Numan and Carter also define code-switching as “a phenomenon of switching from one language to another in the same speech” (2001, p. 275). Code Switching in EFL Classes Code switching has a close relationship with language classes, especially EFL language classes. According to Milroy and Muysken (1...... middle of article...... fully understand the content and achieve the educational objective. Finally, teachers' linguistic proficiency is another factor in their code-switching in class If the teacher has a small vocabulary or lower level of language proficiency, he or she may not be able to use English only in class, so code-switching will be more frequent than regular ones. other competent language teachers In a word, teacher code-switching is completely normal in Chinese EFL classes. We don't need to criticize those who prefer code-switching in English classes. rather, we must carefully examine our own language proficiency, our students' knowledge, and our teaching goals. It is difficult to say whether this is good or bad for encouraging code-switching in classrooms. 'EFL, however, we need to be clear about our educational goals and find ways to appropriately adopt code-switching in different classes.