Abstract: Exact three-dimensional reconstruction algorithms are usually based on the three-dimensional Radon transform which is also widely used in other related fields. However, Radon transform consists of all Radon values placed at the corresponding points. Each value is defined as a plane integral in the object domain. So, the computation of Radon value is rather time expensive using direct integral method. New applications based on it may become convenient if a fast and efficient transformation algorithm is adopted. Therefore, an analytical method is proposed to compute the 3D Radon transform in this paper that is based on 3D S-L phantom including spheres and further compare it with the traditional algorithms of their advantages and disadvantages. Finally, the origin object reconstructed by 3D inverse Radon transform has been proved right by the result from computer simulation.