A novel method for computing kinoform of 3D object based on traditional iterative Fourier transform algorithm is described. The method divides three-dimensional object into many object planes by tomographic technique and treat every object plane as a target image, then iterative computation is carried out between one input plane(kinoform) and several output planes(reconstruction images). A space phase factor is added into iterative process to represent depth characters of 3D object. The experimental result shows that this algorithm computational and convergent velocity is fast. At last, the influences of object planes number and distance to reconstruction quality of kinoform are analyzed, and time-division multiplexing technique is used to reconstruct several object planes based on spatial light modulator.