Abstract: In order to satisfy the high spatial resolution requirements of light wave field in specific observation areas, a diffraction calculation method was presented. Through introducing a virtual optical wave field, it can use the sampling number of original light wave field to represent the diffraction field of arbitrary areas in the observation plane. Simulation experiments were carried out using the proposed method. The calculation results indicate that the method can increase the amount of effective information in the observation areas, and the spatial resolution of the diffraction field obtained by the method of virtual optical wave field can reach 5.2×10^-3 mm/pixel. However, the spatial resolution of the diffraction field obtained by S-FFT is 26.6×10^-3 mm/pixel. Moreover, the experimental results show that the proposed method can achieve better reconstruction performance in color digital holography wavefront reconstruction.