On the impetus of education revolution and online teaching, the flipped classroom mode has been widely concerned. In this paper, the connotation and characteristics of the flipped classroom mode and its related teaching theories are studied. According to the advantages of on-line teaching, the author's teaching practice and the characteristics of the engineering design course, the flipped classroom mode has been practiced, which has been divided into pre-class autonomous learning, classroom learning and after class expansion. Through practice, the teaching goal of taking the students as the centerand cultivating the students' learning ability have been realized.