The reflected spectra of GaN-based distributed Bragg reflector (DBR) for blue light-emitting diodes (LED) are studied by transfer matrix method. The results show that reflective spectra of s-polarized and p-polarized plane waves are the same at normal incidence, but both of them move to high frequency and the difference between them increase rapidly with increasing angle of incidence. Change rate of DBR reflected spectra is related to incident medium, and low refractive index of incident medium has a broader incident response. By modifying the structural parameters, it’s found that correcting the thickness of films by the angle of incidence for increasing wide-angle reflection is a good method. Coupled DBR increases wide-angle reflection at the cost of reducing reflectivity or doubled the thickness of films. Reflected spectra of coupled DBR design is better than that of the conventional DBR design, which is important to enhance light extraction efficiency from LED.