Studies have explored the correlation between students' math interest and their academic performance in grades 4 to 6, emphasizing the role of self-control and resilience as mediators in this relationship. Drawing on interest development and self-regulation theories, we hypothesized that interest directly predicts achievement and indirectly through self-control, resilience, and their chain effect. Using a cross-sectional design, 544 primary school students in grades 4-6 were surveyed using the Mathematics Learning Interest Questionnaire, the Self-Control Scale, and the Resilience Scale, and bivariate correlation analyses, chain mediation effect tests by Process Model 6, and effect analyses by Bootstrap sampling method were applied. There is a significant positive correlation between two and two of the primary school students' math interest, self-control, resilience, and mathematics achievement. The pathways identified were: self-control alone, psychological flexibility alone, and a chain mediation effect of self-control on psychological flexibility. Cultivating primary school students' interest in learning mathematics is conducive to improving primary school students' mathematics achievement, which can directly affect the mathematics achievement of students in grades 4 to 6, and can also be mediated by self-control and resilience.