A novel method is proposed from the perspective of restructuring the image patterns to be modulated to restrain the spectrum overlap. Three sinusoidal gratings with equal phase shift in traditional orthogonal composite grating based phase measurement profilometry (OCGPMP) are replaced by two sinusoidal gratings having π/2 phase shift and a uniform flat image. Moreover, set the spectrum modulated by the flat image between the spectra modulated by two of the sinusoidal gratings. For the flat image, carrier is only modulated by the direct current component. Therefore the spectrum overlap between the adjacent carrier channels is smaller than the traditional OCGPMP. Simulation and experiment results prove the new method can effectively restrain the effect of spectrum overlap, and improve the measurement accuracy more than 1.74 times.