As the third generation of semiconductor material, GaN has many advantages, such as wide bandgap, direct band gap, corrosion resistance and so on. Also, GaN is a very promising material for MOEMS. Because the etching of GaN material is not mature, epitaxial growth on patterned substrate is more helpful for GaN/SOI device. A movable GaN grating on patterned SOI substrate was designed and fabricated with Si micromaching and molecular beam epitaxy process of GaN. The grating actuated by a SOI electrostatic comb-drive micro-actuator could move in two dimensional directions and it could be used as filter in Terahertz wavelength. The period and width of the grating is 16 and 6 μm, respectively. The resonant wavelength is 25901 μm. An horizontal displacement of ±726 μm is obtained at 220 V of horizontal voltage with simulation. When the vertical voltage is 200 V, the displacement is 25 μm. The photoluminescence (PL) measurements of the deposited InGaN/GaN multiple quantum well on patterned SOI substrate are carried out with laser Raman spectrometer. The experimental results show that good optical property of the InGaN/GaN multiple quantum well. A wide emission wavelength from 350 to 500 nm is demonstrated. With the increase of temperature from 10 K to room temperature, the photoluminescence peak position appears a tendency of “S” shape because of the localized effect and band shrink in the InGaN/GaN quantum well.