Objective:To explore the surgical method and therapeutic effect of repairing thumb pulp defect with pedicled transposition of radial proper palmar digital artery flap of middle finger.Methods:Since June, 2006 to May, 2020, 17 cases(17 fingers) with thumb pulp defect were repaired by pedicled transposition of radial proper palmar digital artery flap of middle finger. The sizes of flap ranged from 1.5 cm × 1.5 cm to 4.2 cm × 2.0 cm. The antegrade pedicled flap of radial proper palmar digital artery of middle finger was used in 2 cases and the retrograde pedicled flap of middle finger was used in 15 cases. After the flap was resected, the donor sites were covered with a medium thickness skin graft transferred from the wrist or elbow. The skin graft did not need to be packed. The dorsal branch of the digital nerve was included in the flap and it was anastomosed with the proper nerve of the injured thumb stump. After 16-22 days of the operation, the pedicles were cut off. The patients were instructed to perform digit function exercise after the pedicle was cut off. After the operation, the patients were included in regularly follow-up through outpatient visit, telephone or WeChat interview. The appearance and sensation of the thumb and finger pulps and the function recovery of the thumb and finger joints were observed through the followed-ups.Results:All 17 flaps and donor site skin grafts survived over 3 to 32 months of follow-up. The flaps achieved good texture and natural appearance. The TPD recovered to 5~11 mm. According to the Michigan Hand Function Questionnaire, all the 17 patients were very satisfied with the overall appearance and function of the hands. According to TAM, the 17 cases were all in excellent.Conclusion:Repairing thumb pulp defect with radial proper palmar digital artery pedicled flap of middle finger, the flap resection is simple, and the donor site is hidden. The appearance and texture of flap is good. It is a safe, effective and good method.