In the academic environment, emotions will appear in various situations encountered by individuals. In order to make all kinds of academic emotions play an active role as far as possible, researchers began to pay attention to the research topic of emotional regulation. Many studies have shown that grade and gender are related to the use of emotional expression strategies (expression inhibition and expressive enhancement). However, the results remain unclear. Previous studies have also found that emotional states themselves have an impact on the tendency to evaluate and the psychological resources required for the emotional regulation process. In addition, according to the model of emotion regulation process, emotional expression strategies are important regulation strategies after the generation of emotions. Therefore, in order to make students aware of the importance of emotional expression strategies for their learning and healthy psychological development, and learn to regulate emotions in an appropriate or adaptive way, it is necessary to explore and reveal the developmental characteristics of academic emotional expression strategies, and to examine the role of academic emotions in the use tendency of academic emotional expression strategies. Therefore, in order to investigate the gender and grade differences in academic emotion expression strategies, and the relationship between academic emotions and academic emotional expression strategies, a total of 3004 students from 7th to 12th grade were recruited from ten middle schools in Guangdong, Guangxi, Yunnan, Shananxi, Henan and Jilin and participated in this study. They were measured using two questionnaires concerning academic emotions questionnaire and academic emotion regulation questionnaire. The main findings of the study were as following: (1) Regardless of the emotion valence, there are slight differences in the use of expressive suppression and expressive enhancement among different genders and grades. (2) Positive academic emotions were positively predicted expression suppression and expressive enhancement. Negative academic emotions were positively predicted expressive enhancement, not expression suppression. These results not only suggested the gender and grade differences in academic emotional expression strategies of middle school students, but also emphasized the importance of emotion valence in regulating academic emotions, which lays a foundation for follow-up research.