The results indicated that up‐regulated DNM1L expression in STs was associated with RA severity, and DNM1L deficiency altered mitochondrial morphology and reduced ROS production, inflammatory responses, and autophagy in FLSs by down‐regulating the AKT/IKK/NFKBIA/NF‐κB signalling. Here, NFKBIA is linked to rheumatoid arthritis.