The purpose of this clinical trial is to determine whether transcutaneous auricular vagus nerve stimulation (taVNS) is suitable for improving sleep disorders in patients with rheumatoid arthritis (RA). It will also evaluate the safety of taVNS. The main questions it aims to answer are: Can taVNS improve the sleep quality of RA patients? What medical issues might RA patients experience while receiving taVNS treatment? Researchers will compare taVNS with a placebo (a similar substance that does not contain the actual treatment) to see if taVNS is effective in improving sleep disorders in RA patients. Participants will: Receive taVNS or sham stimulation daily for 4 weeks Keep a daily sleep diary and visit the hospital once a week for check-ups and tests Record their sleep quality and related symptoms This study aims to provide a new, safe, and effective non-drug therapy for sleep disorders related to RA.