Rheumatoid arthritis (RA) is a chronic autoimmune disease dominated by chronic inflammation of the synovium of the joints. Methotrexate (MTX) is the most widely used in the treatment of RA. This study systematically evaluated the clinical efficacy of MTX on RA and provided a theoretical basis for the clinical treatment of RA. Four English databases (PubMed, Embase, Medline, and Web of Sciences) were searched for randomized controlled trials (RCTs) on MTX treatment of RA published from the date of establishment of the database to 2021. The Cochrane Handbook 5.0.2 was used to perform risk bias evaluation and Review Manager 5.3 was used to conduct a meta-analysis. A total of eight articles were included. The meta-analysis showed that, compared to the control group, the number of patients with DAS28-ESR ≤2.6 [erythrocyte sedimentation rate (ESR)] in the MTX alone or MTX combined treatment groups was higher, and the incidence of adverse events was also higher. However, there was no significant difference in the level of alanine aminotransferase (ALT) after treatment versus the control group. MTX alone or MTX combined treatment can better control the condition of RA patients without causing damage to the patient's blood system or liver and kidney function, but may increase the probability of adverse events.