Background: The traditional anti-inflammation disease-modifying anti-rheumatic drugs (DMARDs) have limited therapeutic effects in rheumatoid arthritis (RA) patients. We previously reported the safety and efficacy of umbilical cord mesenchymal stem cell (UCMSC) treatment in RA patients that were observed for up to 8 months after UC-MSC infusion. The aim of this study is to assess the long-term efficacy and safety of UC-MSC along with DMARDs for the treatment of RA. Methods: 64 RA patients aged 18–64 years were recruited in the study. During the treatment, patients were treated with 40 mL UC-MSC suspension product (2 × 10 cells/ 20 mL) via intravenous injection immediately after the infusion of 100 mL saline. The serological markers tests were used to assess safety and the 28-joint disease activity score (DAS28) and the Health Assessment Questionnaire (HAQ) to assess efficacy. Results: 1 year and 3 years after UC-MSC cells treatment, the blood routine, liver and kidney function and immunoglobulin examination showed no abnormalities, which were all in the normal range. The ESR, CRP, RF of 1 year and 3 years after treatment and anti-CCP of 3 years after treatment were detected to be lower than that of pretreatment, which showed significant change (P < 0.05). Health index (HAQ) and joint function index (DAS28) decreased 1 year and 3 years after treatment than before treatment (P < 0.05). Conclusion: UC-MSC cells plus DMARDs therapy can be a safe, effective and feasible therapeutic option for RA patients.