It is a trend that innovate the traditional bilingual education model and select a new teaching model. Code-switching is a lingual phenomenon when a passages or articles are expressed with two or more language. To guarantee effect of bilingual education and improve education quality, penetration bilingual education was applied during microbiology teaching. Professional English vocabulary, words, passages or articles were introduced to students timely and by measure by the way of language code-switching. The results showed that bilingual teaching mode with language code-switching inspire study emotion and self-confidence of English expression from students.