Intrabody communication (IBC) is a promising approach for realizing information transmission among various wearable or implantable devices within bodyNET. The existing IBC studies are limited to the local or abstract geometric channel model, which is limited to providing efficient channel characteristics for the various transmitting scenarios. The aim of this article is to reconstruct a whole-body model with anatomical features and combine the field-circuit model for investigating the human channel characteristics. A visible human data (VHD) is established by segmentation and 3-D reconstruction of layered tissues. The transmission attenuation was simulated and analyzed through the finite element method. In vivo experiments and phantom experiments were implemented to validate the simulation results. For the on-body communication, the transmission attenuation of the short distance was similar to the low-pass filter’s amplitude-frequency characteristics. For the implantable communication, the consistency coefficient of the attenuation between in-body to on-body and on-body to in-body was higher than 98%, indicating that the body channel is bidirectional. This work provides a repeatable and verified VHD-based whole-body model for the human channel attenuation investigation. It is an essential step for the further development of IBC, such as the transceiver design and the multinodes’ protocol for bodyNET.