To improve the phase accuracy of the reconstructed image of the digital hologram, we investigate the theory and method of the phase reconstruction based on the Hilbert transform, then, verify it by the image plane digital holographic experiment, and finally, compare it with the conventional digital holographic reconstruction method. Results show that Hilbert transform itself posseses the effect of eliminating DC term, therefore the effect of the zero-order frequency spectrum of the hologram which is filtered by frequency domain can be completely eliminated by Hilbert transform. Compared with the conventional Fourier reconstruction mehtod, the accuracy of the phase image can be improved by the reconstruction method based on Hilbert transform, and the standard deviation of the phase image is reduced by 14% in the experiment of red blood cell. This result has an important guiding significance to improve the accuracy of the digital holographic phase reconstruction.