To explore the relationships between autistic traits, self-control, mindfulness, and sleep quality, and the mechanism underlying these relationships, we recruited a sample of 972 junior high school students who completed a survey consisting of the Chinese version of the Comprehensive Autistic Trait Inventory-short form, Self-Control Scale, Child and Adolescent Mindfulness Measure, and Sleep Condition Indicator. The correlation analyses revealed that autistic traits were significantly negatively correlated with self-control, mindfulness, and sleep quality. Conversely, self-control was significantly positively correlated with mindfulness and sleep quality in junior high school students. Mediation analyses indicated that self-control and mindfulness play a chain-mediating role in the association between autistic traits and sleep quality among junior high school students. In conclusion, enhancing levels of self-control and mindfulness is essential for improving sleep quality among junior high school students with high levels of autistic traits.