A patient suffered a sustained soft tissue necrosis and infection at the radial interphalangeal joint of left thumb after laser nevus removal. He was treated in the Department of Orthopaedics, No. 920 Hospital of Joint Logistic Support Force of Chinese People's Liberation Army in February 2020. CTA combined with digital technology of Mimics software was used to accurately locate the perforator of posterior tibial artery septal perforator flap at the appropriate part of the calf and the super flap (1.20 cm×0.80 cm×0.46 cm) for the repair was designed. After 1 year of follow-up, the left thumb flap had no swelling with a satisfactory texture and appearance. The sensory recovered to S 3, and the left thumb movement was completely normal. Only a linear scar remained at the donor site of the calf.