This study investigated the influence of ambient aroma on the academic emotions experienced by middle school students in a practical educational environment. The study was conducted with pre- and post-test experimental design upon subjects in three parallel classes (n = 109) in grade two of a junior school in China. These classes were randomly assigned to one of three experimental conditions (no aroma, daily aroma or aroma every other day). The academic emotions of the students were measured twice using the Adolescent Academic Emotion Questionnaire, once before and once 8 weeks after the use of aromatherapy. Comparison of the change in ratings from baseline to post-test showed that compared to the control class; joy, hope, positive high-arousal academic emotion and relaxation were significantly higher in ambient aroma conditions, and anger and negative high-arousal academic emotion in these conditions were significantly lower. The results suggest that the ambient aroma of sweet orange essential oil can mitigate the reduction in positive academic emotion and improve negative academic emotion in school students over time.