Objective To investigate the effect of circular RNA_003213 (hsa_circ_003213) targeting microRNA-145-5p (miR-145-5p) on the proliferation, migration and invasion of rheumatoid arthritis synovialfibroblasts (RA-FLSs). Methods The levels of hsa_circ_0032131 and miR-145-5p in peripheral blood of RA patients and healthy subjects, RA-FLSs as well as normal human synovial fibroblasts were detected. RA-FLSs were divided into control (NC) group, si-NC group, si-hsa_circ_0032131 group, miR-NC group, miR-145-5p group, anti-miR-NC+si-hsa_circ_0032131 group, anti-miR-145-5p+si-hsa_circ_0032131 group, pcDNA group and pcDNA-hsa_circ_0032131 group. CCK-8 and transwell assays were used to detect the viability, migration and invasion of RA-FLSs. The targeting relationship between hsa_circ_0032131 and miR-145-5p was determined through a dual luciferase reporter assay. Results Compared with healthy subjects, the expression of hsa_circ_0032131 was increased, while the expression of miR-145-5p was decreased in the peripheral blood of RA patients, and the difference was statistically significant (P < 0.05). Compared with normal human synovial fibroblasts, the expression of hsa_circ_0032131 was increased, while the expression of miR-145-5p was decreased in RA-FLSs, and the difference was statistically significant (P < 0.05). Compared with the NC group, the viability, migration and the number of RA-FLSs invasion in the si-hsa_circ_0032131 group were reduced, and the difference was statistically significant (P < 0.05). Compared with the miR-NC group, the viability, migration and the number of RA-FLSs invasion in the miR-145-5p group were reduced, and the difference was statistically significant (P < 0.05). Compared with the anti-miR-NC+si-hsa_circ_0032131 group, the viability, migration and the number of RA-FLSs invasion in the anti-miR-145-5p+si-hsa_circ_0032131 group were increased, and the difference was statistically significant (P < 0.05). Compared with the pcDNA group, the level of miR-145-5p in the RA-FLSs of the pcDNA-hsa_circ_0032131 group was reduced (P < 0.05). The miR-145-5p was a direct target of hsa_circ_0032131. Conclusion Knockdown of hsa_circ_0032131 inhibits the proliferation, migration, and invasion of RA-FLSs by upregulating miR-145-5p.