The phase measurement profilometry (PMP) based on binary gratings with an unequal duty cycle is proposed. The adopted binary gratings have only two grayscales of 0 and 255, and the effect of the gamma nonlinearity on the grayscale of the sinusoidal grating is eliminated. At the same time, the refresh frequency of the projection system can be increased by an order of magnitude. The measurement accuracy of this proposed method is higher than that of the Roach grating defocus projection Fourier transform profilometry and the repeat accuracy is higher than that of the traditional PMP based on sinusoidal gratings.