Objective: To explore the application effect of 3.0T high-resolution magnetic resonance imaging (MRI) technique in the preoperative typing diagnosis of anal fistula. Methods: A total of 80 patients who underwent elective anal fistula surgery in the hospital from July 2021 to March 2023 were selected and completed 3.0T high-resolution MRI examination within 1 week before surgery. Based on the surgical results, the specific detection of anal fistula by 3.0T high-resolution MRI and diagnostic efficiency on preoperative typing were analyzed. Results: The accuracy rates of 3.0T high-resolution MRI in the detection of internal orifice, external orifice, main fistula, fistula branch and abscess in 80 patients with anal fistula were 95.45% (84/88), 100% (67/67), 93.75% (75/80), 90.91% (20/22) and 100% (25/25) respectively. There were no statistical differences in the detection results compared to surgical results (P>0.05). Surgical results showed that there were 36 cases (45.00%) of intersphincteric type, 27 cases (33.75%) of transsphincteric type, 11 cases (13.75%) of suprasphincteric type and 6 cases (7.5%) of extrasphincteric type in 80 patients with anal fistula. 3.0T high-resolution MRI showed 36 cases of intersphincteric type (45.00%), 28 cases of transsphincteric type (35.00%), 11 cases of suprasphincteric type (13.75%), and 5 cases of extrasphincteric type (6.25%). There was no statistical significance in the diagnostic result of anal fistula typing between the two methods (x2=0.109, P=0.991). Kappa test results showed that 3.0T high-resolution MRI had strong consistency in the diagnosis of intersphincteric and transsphincteric anal fistula (Kappa=0.899, 0.806), and had strong consistency in the diagnosis of suprasphincteric and extrasphincteric anal fistula (Kappa=0.789, 0.707). Conclusion: 3.0T high-resolution MRI technique can display the anal fistula lesions, and it is conducive to the accurate typing of anal fistula before surgery, and the typing diagnosis results are highly consistent with postoperative pathology.