A method of structured illumination digital holography includes: (a) providing a structured illumination generating unit and binarization random number encoding unit to generate a coded structured illumination pattern; (b) sampling at least two patterns with phase shift which synthesized as a single structured illumination pattern to be encoded; (c) forming a single digital hologram, and wavefront reconstructing the single digital hologram; (d) performing a compressive sensing approach to recover the object wave with at least two phase shift patterns; and (e) reconstructing the separation of overlap spectrum, to obtain an image covering bandpass spectrum with different high frequency and low frequency.