Critical thinking is an important part of the quality cultivation of engineering students. At present, many colleges and universities in China have gradually realized it, and mainly strengthen the training of students' critical thinking by offering relevant humanities courses, but there are few researches related to this topic through the penetration of engineering professional courses, and they are not deep enough. This study mainly discusses the efficacy of virtual simulation system teaching method in improving critical thinking of engineering students engaged in NC (Numerical Control) machining. It integrates the types of learning activities in the proposed teaching method with the development elements of critical thinking, and then constructs the context-based teaching design along with a self-developed virtual learning environment for the cultivation of students' critical thinking. We also evaluated students' response towards the research topics to investigate its teaching-learning effectiveness and acceptance by student community. Responses from questionnaires were collected from a convenience sample of 63 junior students majoring in NC machining from the author's university. The subsequent empirical study was conducted to exhibit superior results for mostly the cognitive skills of critical thinking. Students' feedback also revealed that students obtain more satisfaction and self-confidence, and demonstrated high positive attitude towards the proposed teaching method, and showed high perceived usefulness of the context-based teaching design to acquire complete, concrete and confident knowledge of NC machining. The findings of this study are valuable for academic institutions and educators to design the virtual visualized lectures and classrooms to enhance students' performance in critical thinking.