In order to promote the English level of undergraduate students of universities in Western China, classroom practice of bilingual teaching for professional course was studied. In this study, "the water pollution control engineering" as pilot courses, classroom practice of bilingual teaching was discussed. Through bilingual teaching, students can grasp the basic terminology and vocabulary of basic theory, the oral communication of basic expertise, of basic terminology and vocabulary of engineering technology and engineering design, English writing of basic expertise, basic terminology and vocabulary of basic environmental protection equipment, and so on. Through bilingual teaching the results and experience achieved can be used as basis and reference for other professional courses to continue practice of bilingual teaching in the classroom.