Objective To investigate the clinical value of magnetic resonance tomography angiography (MRTA) for diagnosing cause of trigeminal neuralgia,and evaluate the ability of 3D-FIESTA,3D-TOF-SPGR and 3D-CE-TOF-SPGR sequences display the three-dimensional spatial relationship between cranial nerves and blood vessels. Methods The 69 patients with trigeminal neuralgia were treated with microvascular decompression (MVD) therapy at the Department of Neurosurgery for the Central Hospital of Enshi Tujia and Miao Autonomous Prefecture from January 2013 to December 2015. MRTA were performed to observe the spatial relationship between the trigeminal nerve and peripheral vascular, and were compared with intraoperative exploration results to evaluate sequence of 3D-FIESTA, 3D-TOF-SPGR and 3D-CE- TOF-SPGR in pre-operative assessment of the ability of relationship between the trigeminal nerve and peripheral vessels. Results MRTA can clearly and simultaneously display the trigeminal nerve and relevant vessels and 3D-FIESTA, 3D-TOF-SPGR and 3D-CE-TOFSPGR sequences display close relationship between the trigeminal nerve and vessels in symptomatic side, the positive were 55(79.7 %), 58(84.1%) and 65(94.2%).While the positive were 4(5.8%), 6(8.7%) and 15(21.7%) respectively in non-symptomatic side. There was no statistical significance in the ability of 3D-FIESTA and 3D-TOF-SPGR for trigeminal nerve and peripheral vascular in symptomatic and non-symptomatic side, while there were statistical difference of 3D-FIESTA and 3D-CE-TOF-SPGR, 3DTOF-SPGR and 3D-CE-TOF-SPGR. Conclusion There was significant value of MRTA to diagnose preoperative cause of trigeminal neuralgia and evaluate selection of surgical indications, 3D-CE-TOF-SPGR sequence can improve display the relationship between trigeminal nerve cisternal segment and the adjacent vessel and trigeminal nerve contacting with peripheral vascular is one of the important factors for trigeminal neuralgia.