Projecting a binary encoding sinusoidal grating calculated by the error diffusion algorithm can not only solve the problem of the effect on nonlinearity of a digital projector but also improve the projection speed by taking the advantage of binary high-speed switching characteristics of digital micro-mirror in digital light processing (DLP) projectors when a digital projector is used in the optical measurement system. As insufficient resolution of projector can degrade the quality of the electronic binary encoding sinusoidal fringe pattern, it influences the measurement accuracy further. Two typical encoding algorithms of error diffusion (Floyd-Steinberg distance weighted and Serpentine raster Sierra Lite) are firstly compared. Then, aimed at the problem that the quality of sinusoidal grating is not good enough to be suitable for the high accuracy measurement when high density binary encoding grating is projected by a DLP projector with lower resolution because of the less number of the sampling points in a grating period, two resolutions are proposed: One is that a cylindrical lens is introduced in the light path of the measurement system to smooth the resulted binary encoded sinusoidal grating along the grating line direction by the optical convolution operation of the lens. The other one is that superimpositing multi-frame binary encoding sinusoidal gratings with different microstructure is used to reduce the standard error of the binary encoding sinusoidal grating and guarantee the accuracy of phase-shift measurement method. The proposed method not only takes the advantage of high-speed characteristics of DLP projectors for projecting binary images, but also improves the sinusoidal characteristic of the binary encoding sinusoidalgrating caused by the limited resolution of DLP obviously. Simulations and experiments both verify the validity of the above two methods.