Abstract: Objective　To discuss the design of 3D printing positioning guide plate in implantation, processing points and its application of cases in the surgical operation of 125I radioactive particle implantation of the advanced head and neck malignancies. Methods　 The design and making steps of 3D printing guide plate by the 21 clinical cases of my department were described，and statistic data of all cases were analyzed. Results　3D print finished implanting the patient 's personalized 125I radioactive particle guide plate, bringing a more convenient surgical operation with higher positioning accuracy. ,And the postoperative review CT showed that the particle implantation was evenly distributed, which was consistent with the preoperative goals. There were no significant implantation deviations in all cases. Of the 18 referral patients, 16 had a significantly reduced tumor, and only 2 had local mucosal rupture. Conclusions　The technology of 3D printing guide plate can effectively substitute for the traditional CT-guided surgery of the 125I radioactive particle implantation. It reduces the risk of radiation exposure around doctors and patients, simplifies the operation technology, which deserves promotion.

Key words: head and neck tumors, 3D print, computer aid design, 125I radioactive particle