〔Abstract〕 Objective To assess the clinical effect and complications of non-coplanar nylon templates guided radioactive125I particles implantation, and these templates made by 3 D printer were applied to assist operation in the treatment of elderly lung cancer patients. Methods From January 2016 to December 2019, 80 elderly patients with advanced lung cancer admitted to our department were randomly divided into three groups.Nylon templates guided particle implantation was used in 19 cases as the template group.As traditional group(21 cases), particles were implanted by manual puncture.In these two groups, all patients were treated with chemotherapy after implantation.The third group, only underwent chemotherapy, was chemotherapy group(40 cases).Local control rate, effectiveness, dosimetric parameters, tumor marker levels and complications were compared among three groups. Results The local control rate, efficiency, and dosimetric parameters of the template group were significantly better than those of the traditional group after operation.The levels of carcinoembryonic antigen(CEA) and cytokeratin 19 fragments(CYFRA21-1) among the template group, the traditional group and chemotherapy group were statistically significant at 6 and 12 months after implantation, while the levels of Neuron Specific Enolase in the three groups were not statistically significant.The difference in the incidence of surgical complications between the template group and the traditional group was not statistically significant, and the difference in the incidence of chemotherapy complications among the three groups was not statistically significant. Conclusion The self-made 3 D printed non-coplanar nylon template guided radioactive particle implantation has good local control effect in elderly patients with lung cancer, satisfactory dose distribution, and few surgery-related complications.It is clinically satisfactory and suitable as an adjuvant treatment method for elderly lung cancer patients.