To solve the limited resolution problem of holographic display using digital micromirror device, a large-size and high-resolution holographic display method is proposed. In this paper, the high-resolution object plane is input using the computer rendering or related transform method, and the resolution of hologram is increased using Fresnel diffraction algorithm and Fourier transform parallel computing. According to the features of the digital micromirror device, the diffraction image sequence is spatially multiplexed and dynamically fused. The resolution and dynamic calculation of the holographic display are effectively improved. Experimental results show that this method can achieve large-size and high-resolution dynamic holographic display effect, breaking through the inherent limitation of pixel number and resolution for digital micromirror device. 8K or higher resolution reconstructed image can be displayed using the 2K digital micromirror device, and the size can reach 82 mm or even larger.