Objective Explore the application of diffusion tensor imaging (DTI) positioning in the resection of acoustic neuroma and its preventive effect on facial nerve dysfunction. Methods We selected 106 patients with acoustic neuroma who were treated in our hospital from January 2017 to January 2020, and collected clinical data of the patients. DTI was used to locate the positional relationship between the facial nerve and the tumor before operation, and compared with the intraoperative facial nerve electrophysiological monitoring results to analyze the consistency of the two detection results. Surgery was performed on patients to analyze the effect of surgery, the probability of facial nerve preservation, and the facial nerve function of patients after surgery. Results Facial nerves were located on the ventral side of the tumor, of which 25 cases were located in the upper ventral upper part, 44 cases were located in the central ventral side, 19 cases were located in the lower ventral side, 12 cases were located on the upper pole of the tumor, and 6 cases were located on the lower pole of the tumor. There were 100 cases where the preoperative DTI results were consistent with the intraoperative neuroelectrophysiological monitoring results, and the coincidence probability was 94.34%; There were 6 cases of non-conformity, the probability of non-conformity was 5.66%, and the difference was not statistically significant (P>0.05). There were 73 cases of total tumor resection, 28 cases of near total resection, 5 cases of subtotal resection, and no partial resection. All patients achieved anatomical preservation of the facial nerve after surgery. The probability of good neurological function before surgery was 89.62%; At 2 weeks, 3 months, 6 months, and 1 year after surgery, the probability of good facial nerve function was 74.53%, 46.23%, 53.77%, and 85.85%, respectively; The difference in facial nerve function grading before and after surgery was statistically significant (P<0.05). Conclusion It is more accurate to locate the position of the facial nerve through DTI before operation, and the operation effect is better and the probability of facial nerve preservation is higher. The facial nerve of the patient has a certain degree of injury after the operation, and the recovery begins 6 months after the operation. Preoperative DTI can effectively locate the positional relationship between the facial nerve and the tumor, guide the clinic to surgically remove the tumor while preserving the facial nerve anatomically, reduce the probability of facial nerve dysfunction in the postoperative patient, and improve the prognosis of the patient.