Abstract: Oxygen parameters of subcutaneous tissue are the important basis to reflect the survival of skin flaps after skin flap transplantation. In order to monitor the oxygen saturation of skin tissue noninvasively, continuously and in real time, theoretical analysis and experimental verification were carried out by near infrared spectroscopy. A current-voltage (I-V) conversion method was proposed and a measurement system was built. The system was used to validate the stability and simulate the vascular embolization of forearm vein occlusion flaps.The results show that, there is a slight difference in tissue oxygen saturation in different parts of different human bodies, it is about 0.05. Under venous occlusion, oxygen parameters of the system tissue change significantly. The maximum decrease is 0.25. The system has high sensitivity. It can continuously measure tissue oxygen saturation parameters and reflect the trend of tissue oxygen change. It can provide important reference for clinical detection of oxygen transport status of skin flaps after operation.