In this paper, it is provided to reconstruct three-dimensional(3D) models of human body by using CT slices and digital images and precisely finding locations of pathological formations such as tumours. 3D image CT reconstruction is an attractive field generally in digital image processing techniques, especially in biomedical imaging. It is necessary to incise a 3D object to obtain detail structure information inside in the process of developing 3D medical visualization system. Visual C++ 6.0 with Visualization Toolkit (VTK) toolbox are used to reconstruct 3D images using the CT slice sequence in PAT format. Cuboids that can be controlled to zoom, move or circumrotate by mouse and used for clipping the object of 3D object. Experiment of tooth and foot shows that the technique can realize the real time.