Abstract： The finite difference time domain method is used to establish the ultra wide band(UWB)transmission system;the input impedance characteristics,transmission characteristics,and electric field distribution in the head wearable device model are analyzed to clarify the UWB transmission mechanism between the devices;and the path loss before and after the simplification of the human body model is compared.The results show that the proposed UWB transmission system has low path loss and stable transmission characteristics,which is of great significance for the development of body surface transmission technology for head wearable devices.