A Drug Synthesis Reaction (DSR) course is required for undergraduates majoring in pharmacy, pharmaceutical engineering, and related majors. It aims to systematically teach students the theoretical knowledge and experimental skills of drug synthesis so that they can better adapt to drug synthesis related work after graduation. Given the shortcomings of traditional two-segment teaching modes, we proposed a new "theoretical teaching + video teaching + experimental teaching" three-segment teaching mode. Specifically, we inserted a 1-2 class hour video teaching segment in the traditional teaching mode. In this segment, teachers will show and explain a teaching video produced by ourselves on the synthesis of star drug Imatinib Mesylate, allowing students to really understand how to synthesize the target-drug step by step from some organic fragments. Through two years of practice, we found that students' DSR course learning effect was significantly improved, whether from the perspective of teachers or students or from the course grades. The surveys also reflect students' great interest and affirmation in this three-segment teaching mode. Of course, as it is still in the early stages of DSR course reform, there are some areas that need to be improved and perfected; we will also continue to reform this course.