This study investigated the association between attachment avoidance and internalizing symptoms and the moderating role of parasympathetic nervous activity (indexed by respiratory sinus arrhythmia withdrawal) in the association. A sample of 109 (Mage = 18.94 years old, SD = 0.92; 69 male) Chinese college students participated in this study. Participants reported attachment avoidance and internalizing symptoms, and their physiological data were collected. Results showed a positive link between attachment avoidance and internalizing symptoms. Further, respiratory sinus arrhythmia (RSA) withdrawal and attachment avoidance interactively predicted internalizing symptoms. Specifically, the positive relation between attachment avoidance and internalizing symptoms was only found among people of low, but not high, levels of RSA withdrawal. Our study highlighted the importance of considering psychophysiological interactions in predicting internalizing symptoms in college students, and contributed to our understanding of the complicated factors underlying college students' internalizing problems. •Attachment avoidance (AA) was positively associated with internalizing symptoms (IS).•The positive relation between AA and IS depends on individual level of respiratory sinus arrhythmia (RSA) withdrawal.•AA was positively related to IS only when RSA withdrawal was low and average, rather than high.