Psoriasis critically influences the psychosocial well-being of patients and reduces their quality of life and work efficiency beyond skin symptoms. However, evidence on the association between life quality based on the Dermatology Life Quality Index (DLQI) and psoriasis severity is limited, particularly in China. This study aimed to explore the association between life quality based on the DLQI evaluation and disease severity among psoriasis patients in China. Four thousand two hundred and thirty psoriasis patients were recruited from the Chinese National Clinical Research Center for Skin and Immune Diseases from 2020 to 2021. Information was collected by applying a structured questionnaire and onsite physical examination. Data analysis was performed by using SAS software (version 9.4; SAS Inc., Cary, NC), and statistical significance was set at p < .05. Four thousand two hundred and thirty psoriasis patients were predominantly male (64.6%), with a median age of 38.6 years (interquartile range (IQR): 30.0-50.9). The Psoriasis Area and Severity Index (PASI) score for patients with psoriasis was 7.2 (IQR: 3.0-13.5), and 50% of patients with PASI scored over 7. A total of 84.1% of psoriasis patients reported that psoriasis affected their quality of life from mild to severe. The DLQI scores among psoriasis patients were positively correlated with PASI scores (r = 0.43, p < .01), both in patients of different sex and different age. Logistic regression analysis with the adjustment of potential confounders indicated that patients with higher PASI score also had higher DLQI score, the odds ratio (OR) were 1.69 (95% confidence interval (CI): 1.38-2.08) for patients with PASI score 3-7, 2.61 (95% CI: 2.10-3.25) for patients with PASI score 8-11 and 3.36 (95% CI: 2.78-4.07) for patients with PASI score ≥12, compared with patients with PASI score <3, respectively. Life quality based on DLQI evaluation positively correlated with disease severity among patients with psoriasis, especially among male patients and those with higher body mass index. Therefore, we recommend that clinicians treat the DLQI as an important indicator during patient treatment.