Objective:To design an oral methotrexate auxiliary device and explore the effect of methotrexate in patients with rheumatoid arthritis.Methods:Totally 30 patients with rheumatoid arthritis were selected and observed continuously for 12 months, from January to June in 2021, in the Affiliated Changzhou No. 2 People ′s Hospital of Naijing Medical University. The subjects took the medicine routinely in the first 6 months after entering the group, and the methotrexate oral drug assistant device was given in the latter 6 months to remind them to take the medicine correctly. Medication administration of patients before and after using the auxiliary device was compared, and the evaluation indexes such as disease activity, medication compliance and anxiety were observed. Results:Without the auxiliary device, there were 14 cases (46.67%) of medication error, 13 cases (43.33%) of medication time error, 9 cases (30.00%) of missed administration, while after the use of the auxiliary device, there were 4 cases (13.33%) of medication error, 2 cases (6.67%) of medication time error and 2 cases (6.67%) of missed administration, and the differences were statistically significant ( χ2=8.10, 9.09, 5.14, all P<0.05). Moreover, before using the auxiliary device, the scores of disease activity and medication compliance were 3.92 ± 0.95, 84.97 ± 6.49, respectively, while with the help of the auxiliary device, those scores changed to 3.29 ± 0.83, 92.40 ± 4.17 respectively. All the differences were statistically significant ( t=10.06, -10.37, both P<0.01). 16 cases (53.33%) were anxious after using the assistive device, which was also better than 26 cases (86.67%) before using the device. The difference was statistically significant ( χ2=8.10, P<0.01) . Conclusions:Oral administration aid for methotrexate can help rheumatoid arthritis patients to take methotrexate correctly and safely, reducing disease activity and anxiety, improving drug compliance. It is worthy to clinical promotion.