To simplify the calculation of three-dimensional objects and accelerate the computation time about holographic data, a method for spectrum extraction of 3D object with object points was presented. The spectrum method for model was analyzed and the spectrum could be derived from the integration of a perspective image multiplied by a factor of a specific plane wave. The algorithm for perspectives generation of an object was discussed in detail. The parallel computation with Matlab language was used to reduce the computational burden. And a 3D bird was tested with this method to generated perspectives. Based on the spectrum distribution of real object, a simplified extraction model with high order Gauss probability distribution was proposed which could hugely reduce the number of perspectives needed to form 3D spectrum. The inverse Fourier transform was used to get complex amplitude distribution in a plane of object field and the result was diffracted and added a reference wave in order to code as Fresnel hologram. The numerical reconstruction and experiment indicate that only 17.75% of the total original views can get high-quality reconstructed image and validity of the proposed method. The 3D spectrum can be coded as different kind of holograms for 3D display and it extends the application of 3D spectrum.