We proposed a method for calculating the computer generated hologram from multi-plane 3D objects by using nonuniform sampled angular spectrum method (NUASM). Both of the hologram plane and the image plane are nonuniform sampled according to the distances and positions of the three-dimensional objects. The nonuniform fast Fourier transform (NUFFT) is used to calculate the angular spectrum propagation from the image plane to the hologram plane and the hologram can be calculated in only one step. Simulation and optical experiment results show that the hologram generated in this way can reconstruct objects on multi - planes simultaneously and separately without axial distortion.