A new approach is presented which combines the computer-generated holography and the synthetic technique for dynamic rainbow holography. Firstly, the object beam distribution data of the practical object are acquired by using 3-D scanner; Secondly, the computer-generated holography is applied to make the main hologram H1 with good quality. Lastly,the traditional method is used to reconstruct the dynamic image. This approach takes the advantage of the computer-generated holography and simultaneously deals with the problem of large viewing angle and reconstruction in white light. Finally,we obtain the elementary experiment result.