To explore the type of adult attachment and the degree of alexithymia in patients with obsessive-compulsive disorder (OCD) and evaluate their relationship. Methods: We assessed 35 OCD patients (OCD group) and 35 normal controls (NC group) using the Intimate Relationship Experience Scale (ECR) and the Toronto Alexithymia 20-item Scale (TAS-20). Results: The attachment avoidance score and attachment anxiety score of the OCD group were higher than those of the NC group (P<0.01). The proportion of unsafe attachment type in the OCD group was significantly higher than that in the NC group (χ2=20.160, P= 0.000). The TAS-20 total score, inability to distinguish between emotions, and inability to describe emotional factors in the OCD group were significantly higher than those in the NC group (P<0.05). In the OCD group, there was a positive correlation between attachment avoidance and inability to distinguish between emotions and emotional description (P<0.05) and a positive correlation between attachment anxiety and inability to identify emotions (P<0.05). Conclusion: OCD patients predominantly show insecure attachment and suffer alexithymia.