Objective To explore the related influencing factors of medication compliance and knowledge-attitude-practice nursing measures in outpatients with psoriasis. Methods The clinical data of 86 patients with psoriasis treated in our hospital from January 2021 to December 2023 were retrospectively analyzed. Morisky Medication Adherence Scale (MMAS-8) was used to evaluate medication compliance at the next review after treatment. According to patients' medication compliance, they were divided into poor medication compliance group and good medication compliance group. The basic data of age, gender, education level, marital status, type of combined medication, family monthly income per capita, self-efficacy, social support, disease and drug knowledge level, combined anxiety or depression were collected from the two groups. Logistic regression analysis was carried out to obtain the high-risk factors affecting medication compliance. Results A total of 86 patients were included, of 39 patients (45.35%) had poor medication compliance and 47 patients (54.65%) had good medication compliance. The proportion of junior high school and below, combined medication types≥3, combined anxiety or depression, poor self-efficacy, poor social support, poor mastery of disease and drug knowledge in the poor medication compliance group was higher than that in the good medication compliance group (P <0.05). Multivariate Logistic analysis showed that junior high school and below, combined medication type≥3, combined anxiety or depression, poor self-efficacy, poor social support, and poor mastery of disease and drug knowledge were high risk factors affecting medication compliance in outpatients with psoriasis (P <0.05 and OR >1). Conclusion The medication compliance of outpatients with psoriasis is closely related to junior high school and below, combined medication types≥3, combined anxiety or depression, poor self-efficacy, poor social support, and poor mastery of disease and drug knowledge. It is also necessary to do a good job in knowledge-attitude-practice nursing intervention to improve patient compliance and ensure the treatment effect.