Abstract: The modulation of quality factor by polarization in the photonic crystal quantum well as (FG)5(GFG)2(GF)5 was studied by using the transfer matrix method. The results show that:when vertical incidence, there are three independent transmission peaks as 100% transmissivity in the photonic crystal quantum well, and it can be an optical filter with three channels. For short wavelength, whether it is TE polarization or TM polarization, the quality factor of optical filtering will be decreased when the angle of incidence be increased. For medium long wavelength, when the angle of incidence be increased, the quality factor of optical filtering will be decreased in TE polarization, but decrease quickly in TM polarization. For long wavelength, all of the TE or TM polarization, the quality factor of optical filtering will be decreased when the angle of incidence be increased, and the growing more faster in TE polarization. When the angle of incidence be increased, the independent transmission peaks will blueshift in both of TE or TM polarization, the photonic crystal can be used as an optical switch. The rules can be designed for new photonic crystal omnidirectional reflector and provide theoretical basis for optical switch device.