With the progresses of the research on "Digital Human", more and more information has been needed for the setting up of the three-dimensional digital models of human organs. In the present paper, based on the method of block mapping with a normal-style bump mapping method, we normalized the vector of the surface of the models, computed offset of the texture coordinates and added to them. The projection of the coordinates to the tangential space complemented the disturbance to the vector of models' surface. The method was proposed with bump texture mapping on the surface of the biological models of organs to improve the impression of the visualization of the organ models and to enhance the sense of reality of the models.