Objective: To explore the therapeutic effect of auricular therapy combined with optimized Yinxieling Formula (sic) on psoriasis vulgaris. Methods: A randomized controlled single-blind clinical trial on 84 outpatients with psoriasis vulgaris was conducted. The patients were randomized to a treatment group (43 cases treated by auricular therapy combined with optimized Yinxieling Formula) and a control group (41 cases treated by optimized Yinxieling Formula alone) according to a random number generated by SPSS 17.0 software. The treatment duration for both groups was 8 weeks. The therapeutic effect was comprehensively measured by the primary outcome measure [Psoriasis Area and Severity Index (PASI) reduction rate] and the secondary outcome measure [PASI, Visual Analogue Scale (VAS), Dermatology Life Quality Index (DLQI), Self-rating Depression Scale (SDS), and Self-rating Anxiety Scale (SAS)]. The outcomes of both groups were obtained and compared before and after the intervention. Results: The PASI reduction rate in the treatment group was 74.4% (32/43), which was higher than that in the control group (36.6%, 15/41, P<0.01). The PASI scores decreased in both groups after treatment and was lower in the treatment group compared with the control group (P<0.01). With stratified analysis, there were significant differences between the PASI scores in the following subgroups: age 18-30, baseline PASI>10 and stable stage (P<0.05). DLQI decreased in both groups on some categories after treatment, but there were no significant differences between the two groups in SDS, SAS and VAS (P>0.05). No obvious adverse reactions were found in either group. Conclusion: The therapeutic effect of auricular therapy combined with Optimized Yinxieling Formula was superior to Optimized Yinxieling Formula alone with no obvious adverse reaction.