Objective To observe the efficacy and safety of Biyukang Mixture Ⅰ on rheumatoidarthritis（RA）.Methods A total of 120 RA with cold-dampness obstruction syndrome inpatients and outpatients received from January 2017 to May 2019 by the Department of Rheumatology,Beijing Hospital of TCM Affiliated to the Capital Medical University were randomly divided into treatment group and control group with randomized, controlled, double-blind, double simulation method, with 60 cases in each group.The treatment group was given Biyukang Mixture Ⅰ, Tripterygium wilfordii polyglycoside tablets placebo and nonsteroidal anti-inflammatory Drugs（NSAⅠDs）, the control group was given Tripterygium wilfordii polyglycoside tablets, Biyukang Mixture Ⅰ placebo and NSAⅠDs both for 12 weeks.A 28-joint Disease Activity Score（DAS28）, health assessment questionnaire（HAQ）and TCM syndrome scores were administered to both two groups at week 2, week 4, week 6, week 8 and week 12. Results At week 12, the total effectiveness of treatment group was 93.3%, that of control group was 90%, the treatment group was better than the control group, but the difference was not statistically significant（P>0.05）;with the treatment getting longer, the effectiveness was increased in TCM syndrome（P<0.05）. The ACR20 patients in treatment group was 93.3%, while that in the control group was 90%. The treatment group was superior to the control group, but the difference was not statistically significant（P>0.05）, with the treatment getting longer, the patients reaching ACR20 became more and more compared with that before the treatment（P<0.05）.Serious adverse events was not found in both groups. Conclusion Biyukang Mixture Ⅰ has similar effect as Tripterygium wilfordii polyglycoside tablets on cold-dampness obstruction syndrome of RA with high safety.