Non-suicidal self-harm (NSSI) is defined as purposeful and socially-unacceptable behaviors, by which individuals repetitively made mild to moderate physical harms to themselves. Past research indicated that negative emotion, emotion regulation capability, and insecure attachment style are important factors predicting NSSI. Nevertheless, the intertwined effects among those factors need to be further explored. The majority of studies examining the mechanism of NSSI have focused mainly on female adolescents, however, it is not clear to what extent the hypothetical model is useful in understanding and explaining the NSSI of male adolescents. It is our goal to disentangle the association between anxious attachment, avoidant attachment and self-harm behavior of male adolescents by taking into account the mediating effects of negative emotion and emotion dysregulation. The results indicated that negative emotion and emotion dysregulation mediated the relationship between insecure attachment style and NSSI behaviors. The findings from the present study highlighted the importance of examining NSSI behaviors among male adolescents. The discussion focused on the mechanisms by which anxious and avoidant attachment style influence male adolescents' NSSI behavior. These results are discussed in the context of their clinical implication and direction for future research.