There are two kinds of method for the science popularizing of intelligent greenhouses: teaching with slides and on-site visits. Teaching with slides is not intuitive and the cost of on-site visits is high. Also, the human-computer interface of the intelligent greenhouse control system is not attractive. Aiming at above problems, an intelligent greenhouse science popularizing system based on virtual reality was developed. The functions of the system included: three-dimensional scene display of greenhouse, three-dimensional simulation of greenhouse equipment, and interaction of greenhouse equipment. The system used a 4-layer software architecture system: model layer, Unity3D service layer, business logic layer and presentation layer. A comparative experiment of virtual reality teaching and slide teaching was conducted. The experiment compared the teaching effects of the two methods through a post-questionnaire survey, and also evaluated the usability of the science popularizing system.The results of the experiment showed that 100% of students who used virtual reality for learning believed that they remained focus during the learning process, 93.3% of students preferred virtual reality to presentations on slides, and 33.3% of students think they had a strong sense of knowledge acquisition.Furthermore, their average score on objective questions was 13.96% higher than that of students who used slides to study.The above results showed that the science popularizing system had high usability.