This study aimed to explore the effectiveness of school-based mindfulness training on learning burnout of Chinese middle school students and the mediating role of psychological resilience between dispositional mindfulness and learning burnout. A cluster randomized controlled trial was conducted with repeated measurement analysis, in which 62 Chinese middle school students in the experimental group received a 10-week school-based mindfulness training. In comparison, 63 students in the control group were randomized to receive no intervention. Learning burnout, dispositional mindfulness, and psychological resilience were measured by Adolescent Student Burnout Inventory, Five Facet Mindfulness Questionnaire, and Resilience Scale for Chinese Adolescents, respectively. The results showed: (1) Compared with the experimental group's pre-test scores and the control group's pretest and posttest scores, the posttest scores of learning burnout in the experimental group significantly decreased. In contrast, the posttest scores of dispositional mindfulness and psychological resilience in the experimental group significantly increased. Meanwhile, the control group gained no significant changes between the pre-and posttest in learning burnout, dispositional mindfulness, and psychological resilience. (2) Dispositional mindfulness was positively related to psychological resilience, while dispositional mindfulness and psychological resilience were negatively associated with learning burnout. (3) The direct effect of dispositional mindfulness on learning burnout and the mediating effect of psychological resilience between dispositional mindfulness and learning burnout were significant. This study suggested that school-based mindfulness training distinctly improves dispositional mindfulness and psychological resilience and alleviates learning burnout in Chinese middle school students. Furthermore, psychological resilience plays a mediating role between dispositional mindfulness and learning burnout.