Objectives：This paper aimed to explore the relationship between personality disorder and personality traits from the perspective of gender differences. Methods: This paper used the principle of convenient sampling. A questionnaire survey was conducted among the undergraduates in Nanjing. SPSS 23.0 and Mplus software were used to carry out t-test, regression analysis and mediation effect analysis. Results: (1) The avoidance personality disorder score of female was significantly higher than that of male, while the scores of schizoid, narcissistic and antisocial personality disorder of female were significantly lower than those of male. In the multi-dimensional trait model, there were gender differences in the 5 dimensions and the 25 characteristics. (2) In female samples, personality disorder was associated with negative affectivity, antagonism and anxiousness, deceitfulness, and callousness. In the male sample, personality disorder was associated with negative affectivity, detachment, disinhibition, separation insecurity, hostility, perseveration, suspiciousness, and intimacy avoidance. (3) The education level of father played a part of the intermediary effect between the antagonism and the personality disorder. (4) The interaction of deceitfulness and callousness played an inverse role in personality disorder. Conclusion: There are gender differences in personality disorder and personality traits.