Based on the silicon bulk micromachining process, a micro programmable grating with tunable blazed angle was designed and optimized. The relative light intensity in the cases of different blazed angle and incident angle was theoretically calculated. Also, the far-field relative light intensity with the changing incident parameters was surveyed by adopting the COMSOL, a finite element simulation tool. The results show that: compared with the surface-micromachined gratings designed in our previous research, the efficient reflecting area is increased by more than 8%, reaching to 83.63%. The realized maximum blazed angle of the designed grating is 6.84°, and the maxmium diffraction efficiency can be 96.67% under the condition of normal incidence with the wavelength of 532nm and the blazed angle with a tunable range of 0-10°.