A scheme of three-dimensional (3D) object encryption and display based on computer generated hologram (CGH) and random phase is presented. In the scheme, according to the reconstruction system of three-dimensional objects, the random phase masks (RPMs) are embedded into spectral information of CGH, then the encrypted CGH (En-CGH) is obtained. When the En-CGH is decrypted, the conjugate random phases as the keys are placed in the right position, and the decryption and reconstruction of three-dimensional objects are realized. The system structure of this scheme is simple. The introduction of RPM improves the security of reconstruction system. The efficiency of the encryption and the capacity of information storage are both improved. The numerical simulation verifies the feasibility of the scheme.