Abstract:The online-offline blending teaching, a new teaching mode combining the advantages of online teaching and offline teaching, adapts to the background of “Internet plus” and the undergraduate education reform in China. Since the establishment of the online course Environmental Engineering Microbiology in Jiangnan University, deep learning-oriented online-offline blending teaching and flipped classroom has been performed for three continuous years. The exploration and practice indicated that the reorganization of course content, the integration of teaching resources, the combination of diverse teaching methods, and the reform of examination way in this teaching mode benefited the cultivation of students’ abilities of self-study, problem solving, team cooperation and communication as well as international horizon. In this paper, we summarized and reviewed the blending teaching and flipped classroom in this course, hoping to provide valuable references for the reform of teaching mode in specialized courses of environmental science and engineering in colleges and universities of China.