Objective To explore the relationship between parenting style， moral judgment ability and perfectionism degree of obsessive-compulsive disorder （OCD） patients， and to compare the differences between the patients and healthy people. Methods A total of 100 patients with OCD in the psychology outpatient department of a 3A hospital in Beijing from January to October 2021 were selected by convenience sampling method as study group. At the same time， 100 healthy controls were recruited as the control group. The Chinese standard version of Moral Judgment Test （MJT）， Egma Minnen av Bardndosnauppforstran （EMBU） and Chinese version of Frost's Multidimensional Perfectionism Scale （FMPS-C） were used to compare the differences of moral judgment ability， parenting style and perfectionism degree between the two groups. Pearson correlation and multiple linear regression were used to analyze the relationship among parental rearing style， perfectionism， and moral judgment ability of OCD patients. Results The score of FMPS-C non adaptability dimension in the study group was higher than that in the control group ［（76.2±7.3） vs （58.3±12.6）］. The scores of FMPS-C adaptability dimension and Chinese standard version of MJT in the study group were lower than those of the control group ［（18.5±3.1） vs （23.8±4.7），（9.5±1.7） vs （14.7±6.3）］. The differences were statistically significant （P ＜ 0.01）. The scores of father's punishment， severity， excessive interference， refusal， denial and overprotection factors in EMBU of the study group were higher than those of the control group， and the differences were statistically significant （P＜ 0.05）. The scores of excessive interference and protection， refusal， denial， punishment and severity of mothers were higher than those of the control group， and the differences were statistically significant （P ＜ 0.05）. Excessive intervention and protection， refusal， denial， punishment and severity of mothers of OCD patients were positively correlated with the degree of nonadaptive perfectionism （r=0.954， 0.412， 0.419； P＜ 0.01）， and negatively correlated with moral judgment ability （r=-0.853， -0.244， -0.358； P＜ 0.05）. Punishment， severity， excessive interference， refusal， denial， and excessive protection of fathers of OCD patients were positively correlated with the degree of nonadaptive perfectionism （r=0.304， 0.240， 0.690， 0.248； P＜0.05）. Father's refusal and denial were negatively correlated with moral judgment （r=-0.717， P＜ 0.01）. The excessive intervention and protection， refusal and denial， punishment and severity of mothers， and refusal and denial of fathers partially mediate the moral judgment ability through the degree of nonadaptive perfectionism （P＜ 0.05）. Conclusions The moral judgment ability of patients with OCD was lower than that of healthy people； Parents' excessive control， denial， punishment and other parenting styles and nonadaptive perfectionism were higher than those of healthy people. Parenting style partially affects the moral judgment ability of OCD patients through the degree of nonadaptive perfectionism.