Abstract: In gun shooting cases, in addition to the traditional inspection of guns,bullets and shells, the inspection of shooting residues and ballistics is also a crucial part and an important research object of forensic science. The traditional gun and bullet trace inspection course focuses on explaining the inspection of bullets and shells, combined with a small amount of introduction to gun structure and ballistics. It does not incorporate relevant knowledge of shooting residues into the course, so it is difficult to form a system. This article innovatively proposes a new exploration of the teaching mode of gun and bullet trace inspection course for undergraduate students in police colleges, so as to form a scientific and complete teaching system. At the same time, combined with ideological and political education, virtual reality teaching methods are used to overcome the difficulties of practical teaching in this course, so as to achieve the teaching effect of applying knowledge to practice and serving combat.