Projector defocusing technique can eliminate projector nonlinearity in three-dimensional measurement of grating projection. However, the high frequency harmonics produced by binary grating can weaken the sinusoidal feature of grating and generate phase errors. A new method is proposed to generate binary grating patterns. Based on symmetry and periodicity of sinusoidal grating pattern, this method selects a smaller binary patch. Then the selected patch is randomly initialized, the binary patch is optimized through multi-pixels′ mutation, and the binary grating pattern of full size pattern is generated according to the optimized binary patch. Finally, combined with phase-shifting algorithm, required phase information for three-dimensional measurement is retrieved under the environment of defocusing measurement for the projector. Compared with the generation method of traditional binary grating patterns, the proposed method can certify high-quality phase information acquisition and suitable for the measurement environment of different defocusing amounts. Simulations and experiments are carried out to verify that the proposed method is more proper for three-dimensional measurement of defocused projection.