This study focused on China's higher education system and explored if personality traits were a mediator of the relationship between motivational mechanisms and continuous improvement, and further explored if leadership change was a moderator of the relationship between personality traits and continuous improvement of the motivations and student study processes. In this paper, partial least squares (PLS) was the primary methodology used to test mediation and moderation. This study analysed 350 samples even though a large sample may cause an evaluative error in the mediation effect when using PLS. For this reason, we further adopted the Sobel test to verify this effect. According to the test results, in addition to motivational mechanisms having a positive effect on continuous improvement of the motivations and student study processes, personality traits are a mediator that influences the effect of motivational mechanisms on the continuous improvement of the motivations and student study processes. Furthermore, we proved that leadership change is a moderator between personality traits and continuous improvement of the motivations and student study processes. In addition, we discussed the relationship between mediation and moderation effects of different personality traits and leadership change.