Objective To investigate the value of mixed reality （MR） technique in assisting the surgical treatment process of craniocerebral tumor.Methods A total of 59 patients with craniocerebral tumor who were diagnosed and treated in Department of Neurosurgery， The Third Affiliated Hospital of Kunming Medical University， from October 2022 to December 2023 were enrolled， and according to whether MR technique was used to assist surgical treatment， they were divided into MR technique group and conventional surgery group. For the 27 patients in the MR technique group， 3D slicer was used for tumor visualization， preoperative tumor localization， skin incision design， and preoperative planning； for the 32 patients in the conventional surgery group， surgical treatment was performed by the surgeon in charge based on his/her surgical experience. Related indicators were recorded for both groups， including intraoperative blood loss， time of operation， bone flap area， length of postoperative hospital stay， and the incidence rate of postoperative complications.Results The MR technique group had a significantly smaller median bone flap area than the conventional surgery group ［20.92 （15.29， 28.54） cm² vs 33.42 （20.24， 39.95） cm²， P = 0.016］. Compared with the conventional surgery group， the MR technique group had a significantly shorter length of postoperative hospital stay ［11 （8， 15） days vs 16 （13， 18.75） days， P = 0.000］ and a significantly lower incidence rate of postoperative complications （11.1% vs 40.6%， P = 0.011）.Conclusion MR technique for assisting the surgical treatment of craniocerebral tumor can help to achieve tumor visualization， assist in tumor localization， formulate the surgical plan， and perform surgical simulation， and it is of great significance in achieving the maximum degree of safety in tumor resection.