Objective To investigate the effectiveness of three-dimentional (3D) printed personalized guide plate to assist wrist arthroscopic repair for Palmer type IB triangular fibrocartilage complex (TFCC) injury. Methods A retrospective analysis was conducted on the clinical data of 20 patients with Palmer type IB TFCC injuries admitted between January 2023 and March 2024 who met the selection criteria. Among them, 13 were male and 7 were female; ages ranged from 23 to 35 years, with a mean age of 30.3 years. All patients had a history of trauma, 12 cases involved falls and 8 cases involved sprains. All patients demonstrated a positive “piano key sign”. MRI revealed deep ulnar-side tears of the TFCC. Conservative treatment for 6 weeks yielded poor or no clinical improvement. The interval from injury to surgery ranged from 2 to 9 months, with a mean of 5.0 months. Patients underwent wrist arthroscopic repair assisted by 3D printed personalized guide plate. Functional recovery was assessed preoperatively and postoperatively using the visual analogue scale (VAS) score for pain, modified Mayo wrist score, and range of motion (ROM) measurements for wrist flexion-extension, ulnar-radial deviation, and pronation-supination. At last follow-up, MRI was performed to evaluate the healing of TFCC. Results All 20 patients underwent successful surgery without complications such as vascular or nerve injury, fracture, incisional infection, or joint stiffness. All patients were followed up 9-18 months (mean, 12.4 months). At last follow-up, patients demonstrated significant improvements in VAS scores, modified Mayo wrist scores, palmar flexion-dorsiflexion ROM, ulnar deviation-radial deviation ROM, and pronation-supination ROM compared to preoperative levels (P<0.05). MRI at last follow-up showed preserved TFCC continuity, excellent healing, and secure fixation. Conclusion 3D-printed personalized guide plate significantly improve outcomes in wrist arthroscopic TFCC repair for Palmer type ⅠB injuries. They enable high-quality suturing, facilitate anatomical reconstruction, and markedly enhance wrist function.