The 8th rib cartilage was sometimes insufficient to construct a complete external helix in ear reconstruction for microtia. The aim of this study was to investigate the splicing technique of 8th rib cartilage in modified Nagata method stage I. Between September 2022 and May 2023, 231 consecutive patients with microtia underwent auricular reconstruction with modified Nagata method stage I. Thirty-four patients with insufficient 8th rib cartilage were screened out by three-dimensional (3D) computed tomography preoperatively, who were included in the study prospectively. The 8th rib was spliced to create the external helix when fabricating the ear framework in the stage I surgery for the 34 patients. The median duration of follow-up was 12.1 months (8-15 months). There were no perioperative complications in our study. During follow-up, all patients had satisfying outcomes, with no inward collapse, displacement, or absorption of the spliced external helix. The splicing point was not obvious. It was safe and effective to splice the 8th rib cartilage for external helix of the cartilage framework in ear reconstruction for microtia.