Digital human body modeling method for assigning density, constituent by CT value

The invention discloses a digital body modeling method for using CT values to endow density and composing components, comprising: after obtaining a colorful picture and a CT film of human body, registering and dividing the colorful picture, marking important organs or tissues of human body; converting the CT values of the CT film after colorful picture registration, to obtain the density and composing components of the organs or tissues. The inventive digital body model can actually represent the three-dimension geometric information of human body, and can actually represent the internal anatomical structure of human body, which can be used to evaluate body radiation dose in nuclear medicine and radiation protection fields.