A computer-generated holographic(CGH) algorithm based on layer structure using angular spectrum propagation theory was proposed in order to improve the calculation speed and the reconstruction quality. The 3D scene was stratified, and the sub holograms of each layer were obtained by angular spectrum diffraction method. The hologram of the whole 3D scene was generated by the superposition of these sub holograms. Because there was no paraxial approximation in angular spectrum diffraction method, the algorithm could be applied to different kinds of 3D models. Besides, the computational complexity of the algorithm depended on the number of layers rather than the complexity of 3D scenes, so the computation speed could be increased by 2-3 orders of magnitude. The algorithm provides an effective solution for dynamic 3D display.