Introducing three-dimensional modeling technology into the teaching of modern engineering graphics is a hot topic for graphics areas in recent years. Three-dimensional geometric modeling principles, methods, and skills will be integrated and infiltrated to modern engineering graphics course, and this will form a new teaching theory, content and process with modern engineering graphics teaching trends. The teaching reform of modern engineering graphics in the three- dimensional modeling environment must be imperative. This paper analyzes the shortcomings of a traditional teaching system, and explores the teaching mode which three-dimensional modeling is as the mainline and integrates two-dimensional design. Also proposes a combination of teaching methods, and makes the exploration of teaching reform.