Abstract: In response to the lack of an accurate human impedance model, the inability of residual current protection equipment in low-voltage distribution networks to identify electrocution characteristics, and the inability to use humans as electrocution test objects, a human electrocution dynamic impedance model based on animal electrocution test data and fitted with the least squares method is established. The dynamic impedance model is improved by the electrocution channel composition based on the high similarity of electrical characteristics and anatomy between humans and animals such as pigs and sheep. Compared with the existing human impedance model, the human electrocution dynamic impedance model is more accurate in describing the impedance change within a short time of electrocution, and can highlight the time-varying characteristics of human impedance within a short time of electrocution. Physical simulations show that the human dynamic impedance model is able to characterize the human impedance trend both within a short period of time and over a long period of time. It is a reference value for the development of a new generation of residual current protection devices for the human body and other living organisms.